Eugeniu Rosca erosca@de.adit-jv.com wrote:
Hello,
On Thu, Jun 03, 2021 at 12:15:07PM -0500, Andrew Gabbasov wrote:
FunctionFS device structure 'struct ffs_dev' and driver data structure 'struct ffs_data' are bound to each other with cross-reference pointers 'ffs_data->private_data' and 'ffs_dev->ffs_data'. While the first one is supposed to be valid through the whole life of 'struct ffs_data' (and while 'struct ffs_dev' exists non-freed), the second one is cleared in 'ffs_closed()' (called from 'ffs_data_reset()' or the last 'ffs_data_put()'). This can be called several times, alternating in different order with 'ffs_free_inst()', that, if possible, clears the other cross-reference.
[Skip some comment...]
I confirm there are at least two KASAN use-after-free issues consistently/100% reproducible on v5.13-rc4-88-gf88cd3fb9df2:
https://gist.github.com/erosca/b5976a96789e574b319cb9e076938b5c https://gist.github.com/erosca/4ded55ed32f0133bc2f4ccfe821c7776
These two can no longer be seen after the patch is applied.
In addition, below static analysis tools did not spot any regressions: cppcheck 2.4, smatch v0.5.0-7445-g58776ae33ae8, make W=1, coccicheck
Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com
-- Best regards, Eugeniu Rosca
It like there is similar issue on kernel-4.14 reported by our customer (Android). The back trace are similar. It looks like this patch has fixed issue existed in earlier kernels. Could Engeniu and Andrew help to comment if this fix is suggested to be pick to stable-tree? I've tried to port it onto kernel-4.14, kernel-4.19, and kernel-5.10. But it seems there is some revise work to do. If the origin issue affect multiple LTS kernel versions, then it will be better to be cherry-pick to stable-tree after it has been merged. Thanks!
-----Original Message----- From: Macpaul Lin macpaul@gmail.com Sent: Friday, July 02, 2021 6:02 PM To: Eugeniu Rosca erosca@de.adit-jv.com; stable@vger.kernel.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org; Felipe Balbi balbi@kernel.org; Gabbasov, Andrew Andrew_Gabbasov@mentor.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Macpaul Lin macpaul.lin@mediatek.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH] usb: gadget: f_fs: Fix setting of device and driver data cross-references
Eugeniu Rosca erosca@de.adit-jv.com wrote:
Hello,
On Thu, Jun 03, 2021 at 12:15:07PM -0500, Andrew Gabbasov wrote:
FunctionFS device structure 'struct ffs_dev' and driver data structure 'struct ffs_data' are bound to each other with cross-reference pointers 'ffs_data->private_data' and 'ffs_dev->ffs_data'. While the first one is supposed to be valid through the whole life of 'struct ffs_data' (and while 'struct ffs_dev' exists non-freed), the second one is cleared in 'ffs_closed()' (called from 'ffs_data_reset()' or the last 'ffs_data_put()'). This can be called several times, alternating in different order with 'ffs_free_inst()', that, if possible, clears the other cross-reference.
[Skip some comment...]
I confirm there are at least two KASAN use-after-free issues consistently/100% reproducible on v5.13-rc4-88-gf88cd3fb9df2:
https://gist.github.com/erosca/b5976a96789e574b319cb9e076938b5c https://gist.github.com/erosca/4ded55ed32f0133bc2f4ccfe821c7776
These two can no longer be seen after the patch is applied.
In addition, below static analysis tools did not spot any regressions: cppcheck 2.4, smatch v0.5.0-7445-g58776ae33ae8, make W=1, coccicheck
Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com
-- Best regards, Eugeniu Rosca
It like there is similar issue on kernel-4.14 reported by our customer (Android). The back trace are similar. It looks like this patch has fixed issue existed in earlier kernels. Could Engeniu and Andrew help to comment if this fix is suggested to be pick to stable-tree? I've tried to port it onto kernel-4.14, kernel-4.19, and kernel-5.10. But it seems there is some revise work to do. If the origin issue affect multiple LTS kernel versions, then it will be better to be cherry-pick to stable-tree after it has been merged. Thanks!
-- Best regards, Macpaul Lin
Hello!
Originally this issue was discovered exactly in v4.14 (non-Android), and the fix was developed for that version and later forward-ported to latest mainline 5.13. So, indeed, it makes sense to apply the fix to stable versions (after it has been merged to mainline).
I'm submitting the same patch, back-ported to stable/linux-4.14.y. It can also be applied to linux-4.19.y. While original 5.13 fix is applicable to linux-5.10.y.
Thanks!
Best regards, Andrew Gabbasov
FunctionFS device structure 'struct ffs_dev' and driver data structure 'struct ffs_data' are bound to each other with cross-reference pointers 'ffs_data->private_data' and 'ffs_dev->ffs_data'. While the first one is supposed to be valid through the whole life of 'struct ffs_data' (and while 'struct ffs_dev' exists non-freed), the second one is cleared in 'ffs_closed()' (called from 'ffs_data_reset()' or the last 'ffs_data_put()'). This can be called several times, alternating in different order with 'ffs_free_inst()', that, if possible, clears the other cross-reference.
As a result, different cases of these calls order may leave stale cross-reference pointers, used when the pointed structure is already freed. Even if it occasionally doesn't cause kernel crash, this error is reported by KASAN-enabled kernel configuration.
For example, the case [last 'ffs_data_put()' - 'ffs_free_inst()'] was fixed by commit cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst").
The other case ['ffs_data_reset()' - 'ffs_free_inst()' - 'ffs_data_put()'] now causes KASAN reported error [1], when 'ffs_data_reset()' clears 'ffs_dev->ffs_data', then 'ffs_free_inst()' frees the 'struct ffs_dev', but can't clear 'ffs_data->private_data', which is then accessed in 'ffs_closed()' called from 'ffs_data_put()'. This happens since 'ffs_dev->ffs_data' reference is cleared too early.
Moreover, one more use case, when 'ffs_free_inst()' is called immediately after mounting FunctionFS device (that is before the descriptors are written and 'ffs_ready()' is called), and then 'ffs_data_reset()' or 'ffs_data_put()' is called from accessing "ep0" file or unmounting the device. This causes KASAN error report like [2], since 'ffs_dev->ffs_data' is not yet set when 'ffs_free_inst()' can't properly clear 'ffs_data->private_data', that is later accessed to freed structure.
Fix these (and may be other) cases of stale pointers access by moving setting and clearing of the mentioned cross-references to the single places, setting both of them when 'struct ffs_data' is created and bound to 'struct ffs_dev', and clearing both of them when one of the structures is destroyed. It seems convenient to make this pointer initialization and structures binding in 'ffs_acquire_dev()' and make pointers clearing in 'ffs_release_dev()'. This required some changes in these functions parameters and return types.
Also, 'ffs_release_dev()' calling requires some cleanup, fixing minor issues, like (1) 'ffs_release_dev()' is not called if 'ffs_free_inst()' is called without unmounting the device, and "release_dev" callback is not called at all, or (2) "release_dev" callback is called before "ffs_closed" callback on unmounting, which seems to be not correctly nested with "acquire_dev" and "ffs_ready" callbacks. Make this cleanup togther with other mentioned 'ffs_release_dev()' changes.
[1] ================================================================== root@rcar-gen3:~# mkdir /dev/cfs root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 64.340664] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# cd /dev/ffs root@rcar-gen3:/dev/ffs# /home/root/ffs-test ffs-test: info: ep0: writing descriptors (in v2 format) [ 83.181442] read descriptors [ 83.186085] read strings ffs-test: info: ep0: writing strings ffs-test: dbg: ep1: starting ffs-test: dbg: ep2: starting ffs-test: info: ep1: starts ffs-test: info: ep2: starts ffs-test: info: ep0: starts
^C root@rcar-gen3:/dev/ffs# cd /home/root/ root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 98.935061] unloading root@rcar-gen3:~# umount /dev/ffs [ 102.734301] ================================================================== [ 102.742059] BUG: KASAN: use-after-free in ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.749683] Write of size 1 at addr ffff0004d46ff549 by task umount/2997 [ 102.756709] [ 102.758311] CPU: 0 PID: 2997 Comm: umount Not tainted 5.13.0-rc4+ #8 [ 102.764971] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 102.772179] Call trace: [ 102.774779] dump_backtrace+0x0/0x330 [ 102.778653] show_stack+0x20/0x2c [ 102.782152] dump_stack+0x11c/0x1ac [ 102.785833] print_address_description.constprop.0+0x30/0x274 [ 102.791862] kasan_report+0x14c/0x1c8 [ 102.795719] __asan_report_store1_noabort+0x34/0x58 [ 102.800840] ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.805801] ffs_fs_kill_sb+0x50/0x84 [usb_f_fs] [ 102.810663] deactivate_locked_super+0xa0/0xf0 [ 102.815339] deactivate_super+0x98/0xac [ 102.819378] cleanup_mnt+0xd0/0x1b0 [ 102.823057] __cleanup_mnt+0x1c/0x28 [ 102.826823] task_work_run+0x104/0x180 [ 102.830774] do_notify_resume+0x458/0x14e0 [ 102.835083] work_pending+0xc/0x5f8 [ 102.838762] [ 102.840357] Allocated by task 2988: [ 102.844032] kasan_save_stack+0x28/0x58 [ 102.848071] kasan_set_track+0x28/0x3c [ 102.852016] ____kasan_kmalloc+0x84/0x9c [ 102.856142] __kasan_kmalloc+0x10/0x1c [ 102.860088] __kmalloc+0x214/0x2f8 [ 102.863678] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 102.868990] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 102.873942] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 102.880629] usb_get_function_instance+0x64/0x68 [libcomposite] [ 102.886858] function_make+0x128/0x1ec [libcomposite] [ 102.892185] configfs_mkdir+0x330/0x590 [configfs] [ 102.897245] vfs_mkdir+0x12c/0x1bc [ 102.900835] do_mkdirat+0x180/0x1d0 [ 102.904513] __arm64_sys_mkdirat+0x80/0x94 [ 102.908822] invoke_syscall+0xf8/0x25c [ 102.912772] el0_svc_common.constprop.0+0x150/0x1a0 [ 102.917891] do_el0_svc+0xa0/0xd4 [ 102.921386] el0_svc+0x24/0x34 [ 102.924613] el0_sync_handler+0xcc/0x154 [ 102.928743] el0_sync+0x198/0x1c0 [ 102.932238] [ 102.933832] Freed by task 2996: [ 102.937144] kasan_save_stack+0x28/0x58 [ 102.941181] kasan_set_track+0x28/0x3c [ 102.945128] kasan_set_free_info+0x28/0x4c [ 102.949435] ____kasan_slab_free+0x104/0x118 [ 102.953921] __kasan_slab_free+0x18/0x24 [ 102.958047] slab_free_freelist_hook+0x148/0x1f0 [ 102.962897] kfree+0x318/0x440 [ 102.966123] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 102.971075] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 102.977302] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 102.982344] config_item_put+0x140/0x1a4 [configfs] [ 102.987486] configfs_rmdir+0x3fc/0x518 [configfs] [ 102.992535] vfs_rmdir+0x114/0x234 [ 102.996122] do_rmdir+0x274/0x2b0 [ 102.999617] __arm64_sys_unlinkat+0x94/0xc8 [ 103.004015] invoke_syscall+0xf8/0x25c [ 103.007961] el0_svc_common.constprop.0+0x150/0x1a0 [ 103.013080] do_el0_svc+0xa0/0xd4 [ 103.016575] el0_svc+0x24/0x34 [ 103.019801] el0_sync_handler+0xcc/0x154 [ 103.023930] el0_sync+0x198/0x1c0 [ 103.027426] [ 103.029020] The buggy address belongs to the object at ffff0004d46ff500 [ 103.029020] which belongs to the cache kmalloc-128 of size 128 [ 103.042079] The buggy address is located 73 bytes inside of [ 103.042079] 128-byte region [ffff0004d46ff500, ffff0004d46ff580) [ 103.054236] The buggy address belongs to the page: [ 103.059262] page:0000000021aa849b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0004d46fee00 pfn:0x5146fe [ 103.070437] head:0000000021aa849b order:1 compound_mapcount:0 [ 103.076456] flags: 0x8000000000010200(slab|head|zone=2) [ 103.081948] raw: 8000000000010200 fffffc0013521a80 0000000d0000000d ffff0004c0002300 [ 103.090052] raw: ffff0004d46fee00 000000008020001e 00000001ffffffff 0000000000000000 [ 103.098150] page dumped because: kasan: bad access detected [ 103.103985] [ 103.105578] Memory state around the buggy address: [ 103.110602] ffff0004d46ff400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.118161] ffff0004d46ff480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.125726] >ffff0004d46ff500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.133284] ^ [ 103.139120] ffff0004d46ff580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.146679] ffff0004d46ff600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.154238] ================================================================== [ 103.161792] Disabling lock debugging due to kernel taint [ 103.167319] Unable to handle kernel paging request at virtual address 0037801d6000018e [ 103.175406] Mem abort info: [ 103.178457] ESR = 0x96000004 [ 103.181609] EC = 0x25: DABT (current EL), IL = 32 bits [ 103.187020] SET = 0, FnV = 0 [ 103.190185] EA = 0, S1PTW = 0 [ 103.193417] Data abort info: [ 103.196385] ISV = 0, ISS = 0x00000004 [ 103.200315] CM = 0, WnR = 0 [ 103.203366] [0037801d6000018e] address between user and kernel address ranges [ 103.210611] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 103.216231] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk sata_rc4 [ 103.259233] CPU: 0 PID: 2997 Comm: umount Tainted: G B 5.13.0-rc4+ #8 [ 103.267031] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 103.273951] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 103.280001] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.285197] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 103.290385] sp : ffff800014777a80 [ 103.293725] x29: ffff800014777a80 x28: ffff0004d7649c80 x27: 0000000000000000 [ 103.300931] x26: ffff800014777fb0 x25: ffff60009aec9394 x24: ffff0004d7649ca4 [ 103.308136] x23: 1fffe0009a3d063a x22: dfff800000000000 x21: ffff0004d1e831d0 [ 103.315340] x20: e1c000eb00000bb4 x19: ffff0004d1e83000 x18: 0000000000000000 [ 103.322545] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 103.329748] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000012ef658 [ 103.336952] x11: ffff7000012ef658 x10: 0720072007200720 x9 : ffff800011322648 [ 103.344157] x8 : ffff800014777818 x7 : ffff80000977b2c7 x6 : 0000000000000000 [ 103.351359] x5 : 0000000000000001 x4 : ffff7000012ef659 x3 : 0000000000000001 [ 103.358562] x2 : 0000000000000000 x1 : 1c38001d6000018e x0 : e1c000eb00000c70 [ 103.365766] Call trace: [ 103.368235] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.373076] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 103.377829] ffs_data_closed+0x1ec/0x244 [usb_f_fs] [ 103.382755] ffs_fs_kill_sb+0x70/0x84 [usb_f_fs] [ 103.387420] deactivate_locked_super+0xa0/0xf0 [ 103.391905] deactivate_super+0x98/0xac [ 103.395776] cleanup_mnt+0xd0/0x1b0 [ 103.399299] __cleanup_mnt+0x1c/0x28 [ 103.402906] task_work_run+0x104/0x180 [ 103.406691] do_notify_resume+0x458/0x14e0 [ 103.410823] work_pending+0xc/0x5f8 [ 103.414351] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 103.420490] ---[ end trace 57b43a50e8244f57 ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
[2] ================================================================== root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 54.766480] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 63.197597] unloading root@rcar-gen3:~# cat /dev/ffs/ep0 cat: read error:[ 67.213506] ================================================================== [ 67.222095] BUG: KASAN: use-after-free in ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.229699] Write of size 1 at addr ffff0004c26e974a by task cat/2994 [ 67.236446] [ 67.238045] CPU: 0 PID: 2994 Comm: cat Not tainted 5.13.0-rc4+ #8 [ 67.244431] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.251624] Call trace: [ 67.254212] dump_backtrace+0x0/0x330 [ 67.258081] show_stack+0x20/0x2c [ 67.261579] dump_stack+0x11c/0x1ac [ 67.265260] print_address_description.constprop.0+0x30/0x274 [ 67.271286] kasan_report+0x14c/0x1c8 [ 67.275143] __asan_report_store1_noabort+0x34/0x58 [ 67.280265] ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.285220] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.290172] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.295305] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.300256] __fput+0x304/0x580 [ 67.303576] ____fput+0x18/0x24 [ 67.306893] task_work_run+0x104/0x180 [ 67.310846] do_notify_resume+0x458/0x14e0 [ 67.315154] work_pending+0xc/0x5f8 [ 67.318834] [ 67.320429] Allocated by task 2988: [ 67.324105] kasan_save_stack+0x28/0x58 [ 67.328144] kasan_set_track+0x28/0x3c [ 67.332090] ____kasan_kmalloc+0x84/0x9c [ 67.336217] __kasan_kmalloc+0x10/0x1c [ 67.340163] __kmalloc+0x214/0x2f8 [ 67.343754] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 67.349066] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 67.354017] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 67.360705] usb_get_function_instance+0x64/0x68 [libcomposite] [ 67.366934] function_make+0x128/0x1ec [libcomposite] [ 67.372260] configfs_mkdir+0x330/0x590 [configfs] [ 67.377320] vfs_mkdir+0x12c/0x1bc [ 67.380911] do_mkdirat+0x180/0x1d0 [ 67.384589] __arm64_sys_mkdirat+0x80/0x94 [ 67.388899] invoke_syscall+0xf8/0x25c [ 67.392850] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.397969] do_el0_svc+0xa0/0xd4 [ 67.401464] el0_svc+0x24/0x34 [ 67.404691] el0_sync_handler+0xcc/0x154 [ 67.408819] el0_sync+0x198/0x1c0 [ 67.412315] [ 67.413909] Freed by task 2993: [ 67.417220] kasan_save_stack+0x28/0x58 [ 67.421257] kasan_set_track+0x28/0x3c [ 67.425204] kasan_set_free_info+0x28/0x4c [ 67.429513] ____kasan_slab_free+0x104/0x118 [ 67.434001] __kasan_slab_free+0x18/0x24 [ 67.438128] slab_free_freelist_hook+0x148/0x1f0 [ 67.442978] kfree+0x318/0x440 [ 67.446205] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 67.451156] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 67.457385] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 67.462428] config_item_put+0x140/0x1a4 [configfs] [ 67.467570] configfs_rmdir+0x3fc/0x518 [configfs] [ 67.472626] vfs_rmdir+0x114/0x234 [ 67.476215] do_rmdir+0x274/0x2b0 [ 67.479710] __arm64_sys_unlinkat+0x94/0xc8 [ 67.484108] invoke_syscall+0xf8/0x25c [ 67.488055] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.493175] do_el0_svc+0xa0/0xd4 [ 67.496671] el0_svc+0x24/0x34 [ 67.499896] el0_sync_handler+0xcc/0x154 [ 67.504024] el0_sync+0x198/0x1c0 [ 67.507520] [ 67.509114] The buggy address belongs to the object at ffff0004c26e9700 [ 67.509114] which belongs to the cache kmalloc-128 of size 128 [ 67.522171] The buggy address is located 74 bytes inside of [ 67.522171] 128-byte region [ffff0004c26e9700, ffff0004c26e9780) [ 67.534328] The buggy address belongs to the page: [ 67.539355] page:000000003177a217 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5026e8 [ 67.549175] head:000000003177a217 order:1 compound_mapcount:0 [ 67.555195] flags: 0x8000000000010200(slab|head|zone=2) [ 67.560687] raw: 8000000000010200 fffffc0013037100 0000000c00000002 ffff0004c0002300 [ 67.568791] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 [ 67.576890] page dumped because: kasan: bad access detected [ 67.582725] [ 67.584318] Memory state around the buggy address: [ 67.589343] ffff0004c26e9600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.596903] ffff0004c26e9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.604463] >ffff0004c26e9700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.612022] ^ [ 67.617860] ffff0004c26e9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.625421] ffff0004c26e9800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.632981] ================================================================== [ 67.640535] Disabling lock debugging due to kernel taint File descriptor[ 67.646100] Unable to handle kernel paging request at virtual address fabb801d4000018d in bad state [ 67.655456] Mem abort info: [ 67.659619] ESR = 0x96000004 [ 67.662801] EC = 0x25: DABT (current EL), IL = 32 bits [ 67.668225] SET = 0, FnV = 0 [ 67.671375] EA = 0, S1PTW = 0 [ 67.674613] Data abort info: [ 67.677587] ISV = 0, ISS = 0x00000004 [ 67.681522] CM = 0, WnR = 0 [ 67.684588] [fabb801d4000018d] address between user and kernel address ranges [ 67.691849] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 67.697470] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul sha2_ce sha1_ce evdev sata_rcar libata xhci_plat_hcd scsi_mod xhci_hcd rene4 [ 67.740467] CPU: 0 PID: 2994 Comm: cat Tainted: G B 5.13.0-rc4+ #8 [ 67.748005] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.754924] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 67.760974] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.766178] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 67.771365] sp : ffff800014767ad0 [ 67.774706] x29: ffff800014767ad0 x28: ffff800009cf91c0 x27: ffff0004c54861a0 [ 67.781913] x26: ffff0004dc90b288 x25: 1fffe00099ec10f5 x24: 00000000000a801d [ 67.789118] x23: 1fffe00099f6953a x22: dfff800000000000 x21: ffff0004cfb4a9d0 [ 67.796322] x20: d5e000ea00000bb1 x19: ffff0004cfb4a800 x18: 0000000000000000 [ 67.803526] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 67.810730] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000028ecefa [ 67.817934] x11: ffff7000028ecefa x10: 0720072007200720 x9 : ffff80001132c014 [ 67.825137] x8 : ffff8000147677d8 x7 : ffff8000147677d7 x6 : 0000000000000000 [ 67.832341] x5 : 0000000000000001 x4 : ffff7000028ecefb x3 : 0000000000000001 [ 67.839544] x2 : 0000000000000005 x1 : 1abc001d4000018d x0 : d5e000ea00000c6d [ 67.846748] Call trace: [ 67.849218] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.854058] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.858810] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.863736] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.868488] __fput+0x304/0x580 [ 67.871665] ____fput+0x18/0x24 [ 67.874837] task_work_run+0x104/0x180 [ 67.878622] do_notify_resume+0x458/0x14e0 [ 67.882754] work_pending+0xc/0x5f8 [ 67.886282] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 67.892422] ---[ end trace 6d7cedf53d7abbea ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry-picked from commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149) [agabbasov: Backported to earlier mount API, resolved context conflicts] --- drivers/usb/gadget/function/f_fs.c | 67 ++++++++++++++---------------- 1 file changed, 32 insertions(+), 35 deletions(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 458c5dc296ac..5dfe926c251a 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -247,8 +247,8 @@ EXPORT_SYMBOL_GPL(ffs_lock); static struct ffs_dev *_ffs_find_dev(const char *name); static struct ffs_dev *_ffs_alloc_dev(void); static void _ffs_free_dev(struct ffs_dev *dev); -static void *ffs_acquire_dev(const char *dev_name); -static void ffs_release_dev(struct ffs_data *ffs_data); +static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data); +static void ffs_release_dev(struct ffs_dev *ffs_dev); static int ffs_ready(struct ffs_data *ffs); static void ffs_closed(struct ffs_data *ffs);
@@ -1505,7 +1505,6 @@ ffs_fs_mount(struct file_system_type *t, int flags, }; struct dentry *rv; int ret; - void *ffs_dev; struct ffs_data *ffs;
ENTER(); @@ -1526,19 +1525,16 @@ ffs_fs_mount(struct file_system_type *t, int flags, return ERR_PTR(-ENOMEM); }
- ffs_dev = ffs_acquire_dev(dev_name); - if (IS_ERR(ffs_dev)) { + ret = ffs_acquire_dev(dev_name, ffs); + if (ret) { ffs_data_put(ffs); - return ERR_CAST(ffs_dev); + return ERR_PTR(ret); } - ffs->private_data = ffs_dev; data.ffs_data = ffs;
rv = mount_nodev(t, flags, &data, ffs_sb_fill); - if (IS_ERR(rv) && data.ffs_data) { - ffs_release_dev(data.ffs_data); + if (IS_ERR(rv) && data.ffs_data) ffs_data_put(data.ffs_data); - } return rv; }
@@ -1548,10 +1544,8 @@ ffs_fs_kill_sb(struct super_block *sb) ENTER();
kill_litter_super(sb); - if (sb->s_fs_info) { - ffs_release_dev(sb->s_fs_info); + if (sb->s_fs_info) ffs_data_closed(sb->s_fs_info); - } }
static struct file_system_type ffs_fs_type = { @@ -1620,6 +1614,7 @@ static void ffs_data_put(struct ffs_data *ffs) if (unlikely(refcount_dec_and_test(&ffs->ref))) { pr_info("%s(): freeing\n", __func__); ffs_data_clear(ffs); + ffs_release_dev(ffs->private_data); BUG_ON(waitqueue_active(&ffs->ev.waitq) || waitqueue_active(&ffs->ep0req_completion.wait) || waitqueue_active(&ffs->wait)); @@ -2924,6 +2919,7 @@ static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, struct ffs_function *func = ffs_func_from_usb(f); struct f_fs_opts *ffs_opts = container_of(f->fi, struct f_fs_opts, func_inst); + struct ffs_data *ffs_data; int ret;
ENTER(); @@ -2938,12 +2934,13 @@ static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, if (!ffs_opts->no_configfs) ffs_dev_lock(); ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; - func->ffs = ffs_opts->dev->ffs_data; + ffs_data = ffs_opts->dev->ffs_data; if (!ffs_opts->no_configfs) ffs_dev_unlock(); if (ret) return ERR_PTR(ret);
+ func->ffs = ffs_data; func->conf = c; func->gadget = c->cdev->gadget;
@@ -3398,6 +3395,7 @@ static void ffs_free_inst(struct usb_function_instance *f) struct f_fs_opts *opts;
opts = to_f_fs_opts(f); + ffs_release_dev(opts->dev); ffs_dev_lock(); _ffs_free_dev(opts->dev); ffs_dev_unlock(); @@ -3585,47 +3583,48 @@ static void _ffs_free_dev(struct ffs_dev *dev) { list_del(&dev->entry);
- /* Clear the private_data pointer to stop incorrect dev access */ - if (dev->ffs_data) - dev->ffs_data->private_data = NULL; - kfree(dev); if (list_empty(&ffs_devices)) functionfs_cleanup(); }
-static void *ffs_acquire_dev(const char *dev_name) +static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data) { + int ret = 0; struct ffs_dev *ffs_dev;
ENTER(); ffs_dev_lock();
ffs_dev = _ffs_find_dev(dev_name); - if (!ffs_dev) - ffs_dev = ERR_PTR(-ENOENT); - else if (ffs_dev->mounted) - ffs_dev = ERR_PTR(-EBUSY); - else if (ffs_dev->ffs_acquire_dev_callback && - ffs_dev->ffs_acquire_dev_callback(ffs_dev)) - ffs_dev = ERR_PTR(-ENOENT); - else + if (!ffs_dev) { + ret = -ENOENT; + } else if (ffs_dev->mounted) { + ret = -EBUSY; + } else if (ffs_dev->ffs_acquire_dev_callback && + ffs_dev->ffs_acquire_dev_callback(ffs_dev)) { + ret = -ENOENT; + } else { ffs_dev->mounted = true; + ffs_dev->ffs_data = ffs_data; + ffs_data->private_data = ffs_dev; + }
ffs_dev_unlock(); - return ffs_dev; + return ret; }
-static void ffs_release_dev(struct ffs_data *ffs_data) +static void ffs_release_dev(struct ffs_dev *ffs_dev) { - struct ffs_dev *ffs_dev; - ENTER(); ffs_dev_lock();
- ffs_dev = ffs_data->private_data; - if (ffs_dev) { + if (ffs_dev && ffs_dev->mounted) { ffs_dev->mounted = false; + if (ffs_dev->ffs_data) { + ffs_dev->ffs_data->private_data = NULL; + ffs_dev->ffs_data = NULL; + }
if (ffs_dev->ffs_release_dev_callback) ffs_dev->ffs_release_dev_callback(ffs_dev); @@ -3653,7 +3652,6 @@ static int ffs_ready(struct ffs_data *ffs) }
ffs_obj->desc_ready = true; - ffs_obj->ffs_data = ffs;
if (ffs_obj->ffs_ready_callback) { ret = ffs_obj->ffs_ready_callback(ffs); @@ -3681,7 +3679,6 @@ static void ffs_closed(struct ffs_data *ffs) goto done;
ffs_obj->desc_ready = false; - ffs_obj->ffs_data = NULL;
if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && ffs_obj->ffs_closed_callback)
On Fri, Jul 02, 2021 at 01:49:57PM -0500, Andrew Gabbasov wrote:
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry-picked from commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149)
There is no such commit id in Linus's tree :(
Please resubmit with the correct id.
thanks,
greg k-h
Hello Greg,
-----Original Message----- From: Greg Kroah-Hartman gregkh@linuxfoundation.org Sent: Monday, July 05, 2021 10:08 AM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Fri, Jul 02, 2021 at 01:49:57PM -0500, Andrew Gabbasov wrote:
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry-picked from commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149)
There is no such commit id in Linus's tree :(
Please resubmit with the correct id.
This commit is not yet included to the mainline, it only exists in linux-next: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?...
Could you please advise if I need to somehow denote the linux-next repo in the "cherry picked from" line, or just remove this line, or so far wait and re-submit the patch after the original commit is merged to Linus' tree? BTW, I just noticed that the line contains incorrect "cherry-picked" instead of "cherry picked", so I'll have to re-submit the patch anyway 😉
Thanks!
Best regards, Andrew
On Mon, Jul 05, 2021 at 01:24:10PM +0300, Andrew Gabbasov wrote:
Hello Greg,
-----Original Message----- From: Greg Kroah-Hartman gregkh@linuxfoundation.org Sent: Monday, July 05, 2021 10:08 AM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Fri, Jul 02, 2021 at 01:49:57PM -0500, Andrew Gabbasov wrote:
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry-picked from commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149)
There is no such commit id in Linus's tree :(
Please resubmit with the correct id.
This commit is not yet included to the mainline, it only exists in linux-next: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?...
Could you please advise if I need to somehow denote the linux-next repo in the "cherry picked from" line, or just remove this line, or so far wait and re-submit the patch after the original commit is merged to Linus' tree? BTW, I just noticed that the line contains incorrect "cherry-picked" instead of "cherry picked", so I'll have to re-submit the patch anyway 😉
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
Patches have to be in Linus's tree first before we can take it into a stable tree. Please feel free to resubmit this once it is in a -rc release.
thanks,
greg k-h
Hello Greg,
-----Original Message----- From: 'Greg Kroah-Hartman' gregkh@linuxfoundation.org Sent: Monday, July 05, 2021 1:42 PM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Mon, Jul 05, 2021 at 01:24:10PM +0300, Andrew Gabbasov wrote:
Hello Greg,
-----Original Message----- From: Greg Kroah-Hartman gregkh@linuxfoundation.org Sent: Monday, July 05, 2021 10:08 AM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Fri, Jul 02, 2021 at 01:49:57PM -0500, Andrew Gabbasov wrote:
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry-picked from commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149)
There is no such commit id in Linus's tree :(
Please resubmit with the correct id.
This commit is not yet included to the mainline, it only exists in linux-next: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-
next.git/commit/?id=ecfbd7b9054bddb12cea07fda41bb3a79a7b0149
Could you please advise if I need to somehow denote the linux-next repo in the "cherry picked from" line, or just remove this line, or so far wait and re-submit the patch after the original commit is merged to Linus'
tree?
BTW, I just noticed that the line contains incorrect "cherry-picked" instead of "cherry picked", so I'll have to re-submit the patch anyway 😉
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
Patches have to be in Linus's tree first before we can take it into a stable tree. Please feel free to resubmit this once it is in a -rc release.
Sorry I was one day early before the commit was included to Linus' tree. Now it is there and I'm re-submitting the patch, back-ported to v4.14.
Thanks!
Best regards, Andrew
commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149 upstream.
FunctionFS device structure 'struct ffs_dev' and driver data structure 'struct ffs_data' are bound to each other with cross-reference pointers 'ffs_data->private_data' and 'ffs_dev->ffs_data'. While the first one is supposed to be valid through the whole life of 'struct ffs_data' (and while 'struct ffs_dev' exists non-freed), the second one is cleared in 'ffs_closed()' (called from 'ffs_data_reset()' or the last 'ffs_data_put()'). This can be called several times, alternating in different order with 'ffs_free_inst()', that, if possible, clears the other cross-reference.
As a result, different cases of these calls order may leave stale cross-reference pointers, used when the pointed structure is already freed. Even if it occasionally doesn't cause kernel crash, this error is reported by KASAN-enabled kernel configuration.
For example, the case [last 'ffs_data_put()' - 'ffs_free_inst()'] was fixed by commit cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst").
The other case ['ffs_data_reset()' - 'ffs_free_inst()' - 'ffs_data_put()'] now causes KASAN reported error [1], when 'ffs_data_reset()' clears 'ffs_dev->ffs_data', then 'ffs_free_inst()' frees the 'struct ffs_dev', but can't clear 'ffs_data->private_data', which is then accessed in 'ffs_closed()' called from 'ffs_data_put()'. This happens since 'ffs_dev->ffs_data' reference is cleared too early.
Moreover, one more use case, when 'ffs_free_inst()' is called immediately after mounting FunctionFS device (that is before the descriptors are written and 'ffs_ready()' is called), and then 'ffs_data_reset()' or 'ffs_data_put()' is called from accessing "ep0" file or unmounting the device. This causes KASAN error report like [2], since 'ffs_dev->ffs_data' is not yet set when 'ffs_free_inst()' can't properly clear 'ffs_data->private_data', that is later accessed to freed structure.
Fix these (and may be other) cases of stale pointers access by moving setting and clearing of the mentioned cross-references to the single places, setting both of them when 'struct ffs_data' is created and bound to 'struct ffs_dev', and clearing both of them when one of the structures is destroyed. It seems convenient to make this pointer initialization and structures binding in 'ffs_acquire_dev()' and make pointers clearing in 'ffs_release_dev()'. This required some changes in these functions parameters and return types.
Also, 'ffs_release_dev()' calling requires some cleanup, fixing minor issues, like (1) 'ffs_release_dev()' is not called if 'ffs_free_inst()' is called without unmounting the device, and "release_dev" callback is not called at all, or (2) "release_dev" callback is called before "ffs_closed" callback on unmounting, which seems to be not correctly nested with "acquire_dev" and "ffs_ready" callbacks. Make this cleanup togther with other mentioned 'ffs_release_dev()' changes.
[1] ================================================================== root@rcar-gen3:~# mkdir /dev/cfs root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 64.340664] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# cd /dev/ffs root@rcar-gen3:/dev/ffs# /home/root/ffs-test ffs-test: info: ep0: writing descriptors (in v2 format) [ 83.181442] read descriptors [ 83.186085] read strings ffs-test: info: ep0: writing strings ffs-test: dbg: ep1: starting ffs-test: dbg: ep2: starting ffs-test: info: ep1: starts ffs-test: info: ep2: starts ffs-test: info: ep0: starts
^C root@rcar-gen3:/dev/ffs# cd /home/root/ root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 98.935061] unloading root@rcar-gen3:~# umount /dev/ffs [ 102.734301] ================================================================== [ 102.742059] BUG: KASAN: use-after-free in ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.749683] Write of size 1 at addr ffff0004d46ff549 by task umount/2997 [ 102.756709] [ 102.758311] CPU: 0 PID: 2997 Comm: umount Not tainted 5.13.0-rc4+ #8 [ 102.764971] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 102.772179] Call trace: [ 102.774779] dump_backtrace+0x0/0x330 [ 102.778653] show_stack+0x20/0x2c [ 102.782152] dump_stack+0x11c/0x1ac [ 102.785833] print_address_description.constprop.0+0x30/0x274 [ 102.791862] kasan_report+0x14c/0x1c8 [ 102.795719] __asan_report_store1_noabort+0x34/0x58 [ 102.800840] ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.805801] ffs_fs_kill_sb+0x50/0x84 [usb_f_fs] [ 102.810663] deactivate_locked_super+0xa0/0xf0 [ 102.815339] deactivate_super+0x98/0xac [ 102.819378] cleanup_mnt+0xd0/0x1b0 [ 102.823057] __cleanup_mnt+0x1c/0x28 [ 102.826823] task_work_run+0x104/0x180 [ 102.830774] do_notify_resume+0x458/0x14e0 [ 102.835083] work_pending+0xc/0x5f8 [ 102.838762] [ 102.840357] Allocated by task 2988: [ 102.844032] kasan_save_stack+0x28/0x58 [ 102.848071] kasan_set_track+0x28/0x3c [ 102.852016] ____kasan_kmalloc+0x84/0x9c [ 102.856142] __kasan_kmalloc+0x10/0x1c [ 102.860088] __kmalloc+0x214/0x2f8 [ 102.863678] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 102.868990] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 102.873942] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 102.880629] usb_get_function_instance+0x64/0x68 [libcomposite] [ 102.886858] function_make+0x128/0x1ec [libcomposite] [ 102.892185] configfs_mkdir+0x330/0x590 [configfs] [ 102.897245] vfs_mkdir+0x12c/0x1bc [ 102.900835] do_mkdirat+0x180/0x1d0 [ 102.904513] __arm64_sys_mkdirat+0x80/0x94 [ 102.908822] invoke_syscall+0xf8/0x25c [ 102.912772] el0_svc_common.constprop.0+0x150/0x1a0 [ 102.917891] do_el0_svc+0xa0/0xd4 [ 102.921386] el0_svc+0x24/0x34 [ 102.924613] el0_sync_handler+0xcc/0x154 [ 102.928743] el0_sync+0x198/0x1c0 [ 102.932238] [ 102.933832] Freed by task 2996: [ 102.937144] kasan_save_stack+0x28/0x58 [ 102.941181] kasan_set_track+0x28/0x3c [ 102.945128] kasan_set_free_info+0x28/0x4c [ 102.949435] ____kasan_slab_free+0x104/0x118 [ 102.953921] __kasan_slab_free+0x18/0x24 [ 102.958047] slab_free_freelist_hook+0x148/0x1f0 [ 102.962897] kfree+0x318/0x440 [ 102.966123] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 102.971075] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 102.977302] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 102.982344] config_item_put+0x140/0x1a4 [configfs] [ 102.987486] configfs_rmdir+0x3fc/0x518 [configfs] [ 102.992535] vfs_rmdir+0x114/0x234 [ 102.996122] do_rmdir+0x274/0x2b0 [ 102.999617] __arm64_sys_unlinkat+0x94/0xc8 [ 103.004015] invoke_syscall+0xf8/0x25c [ 103.007961] el0_svc_common.constprop.0+0x150/0x1a0 [ 103.013080] do_el0_svc+0xa0/0xd4 [ 103.016575] el0_svc+0x24/0x34 [ 103.019801] el0_sync_handler+0xcc/0x154 [ 103.023930] el0_sync+0x198/0x1c0 [ 103.027426] [ 103.029020] The buggy address belongs to the object at ffff0004d46ff500 [ 103.029020] which belongs to the cache kmalloc-128 of size 128 [ 103.042079] The buggy address is located 73 bytes inside of [ 103.042079] 128-byte region [ffff0004d46ff500, ffff0004d46ff580) [ 103.054236] The buggy address belongs to the page: [ 103.059262] page:0000000021aa849b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0004d46fee00 pfn:0x5146fe [ 103.070437] head:0000000021aa849b order:1 compound_mapcount:0 [ 103.076456] flags: 0x8000000000010200(slab|head|zone=2) [ 103.081948] raw: 8000000000010200 fffffc0013521a80 0000000d0000000d ffff0004c0002300 [ 103.090052] raw: ffff0004d46fee00 000000008020001e 00000001ffffffff 0000000000000000 [ 103.098150] page dumped because: kasan: bad access detected [ 103.103985] [ 103.105578] Memory state around the buggy address: [ 103.110602] ffff0004d46ff400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.118161] ffff0004d46ff480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.125726] >ffff0004d46ff500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.133284] ^ [ 103.139120] ffff0004d46ff580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.146679] ffff0004d46ff600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.154238] ================================================================== [ 103.161792] Disabling lock debugging due to kernel taint [ 103.167319] Unable to handle kernel paging request at virtual address 0037801d6000018e [ 103.175406] Mem abort info: [ 103.178457] ESR = 0x96000004 [ 103.181609] EC = 0x25: DABT (current EL), IL = 32 bits [ 103.187020] SET = 0, FnV = 0 [ 103.190185] EA = 0, S1PTW = 0 [ 103.193417] Data abort info: [ 103.196385] ISV = 0, ISS = 0x00000004 [ 103.200315] CM = 0, WnR = 0 [ 103.203366] [0037801d6000018e] address between user and kernel address ranges [ 103.210611] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 103.216231] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk sata_rc4 [ 103.259233] CPU: 0 PID: 2997 Comm: umount Tainted: G B 5.13.0-rc4+ #8 [ 103.267031] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 103.273951] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 103.280001] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.285197] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 103.290385] sp : ffff800014777a80 [ 103.293725] x29: ffff800014777a80 x28: ffff0004d7649c80 x27: 0000000000000000 [ 103.300931] x26: ffff800014777fb0 x25: ffff60009aec9394 x24: ffff0004d7649ca4 [ 103.308136] x23: 1fffe0009a3d063a x22: dfff800000000000 x21: ffff0004d1e831d0 [ 103.315340] x20: e1c000eb00000bb4 x19: ffff0004d1e83000 x18: 0000000000000000 [ 103.322545] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 103.329748] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000012ef658 [ 103.336952] x11: ffff7000012ef658 x10: 0720072007200720 x9 : ffff800011322648 [ 103.344157] x8 : ffff800014777818 x7 : ffff80000977b2c7 x6 : 0000000000000000 [ 103.351359] x5 : 0000000000000001 x4 : ffff7000012ef659 x3 : 0000000000000001 [ 103.358562] x2 : 0000000000000000 x1 : 1c38001d6000018e x0 : e1c000eb00000c70 [ 103.365766] Call trace: [ 103.368235] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.373076] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 103.377829] ffs_data_closed+0x1ec/0x244 [usb_f_fs] [ 103.382755] ffs_fs_kill_sb+0x70/0x84 [usb_f_fs] [ 103.387420] deactivate_locked_super+0xa0/0xf0 [ 103.391905] deactivate_super+0x98/0xac [ 103.395776] cleanup_mnt+0xd0/0x1b0 [ 103.399299] __cleanup_mnt+0x1c/0x28 [ 103.402906] task_work_run+0x104/0x180 [ 103.406691] do_notify_resume+0x458/0x14e0 [ 103.410823] work_pending+0xc/0x5f8 [ 103.414351] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 103.420490] ---[ end trace 57b43a50e8244f57 ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
[2] ================================================================== root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 54.766480] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 63.197597] unloading root@rcar-gen3:~# cat /dev/ffs/ep0 cat: read error:[ 67.213506] ================================================================== [ 67.222095] BUG: KASAN: use-after-free in ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.229699] Write of size 1 at addr ffff0004c26e974a by task cat/2994 [ 67.236446] [ 67.238045] CPU: 0 PID: 2994 Comm: cat Not tainted 5.13.0-rc4+ #8 [ 67.244431] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.251624] Call trace: [ 67.254212] dump_backtrace+0x0/0x330 [ 67.258081] show_stack+0x20/0x2c [ 67.261579] dump_stack+0x11c/0x1ac [ 67.265260] print_address_description.constprop.0+0x30/0x274 [ 67.271286] kasan_report+0x14c/0x1c8 [ 67.275143] __asan_report_store1_noabort+0x34/0x58 [ 67.280265] ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.285220] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.290172] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.295305] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.300256] __fput+0x304/0x580 [ 67.303576] ____fput+0x18/0x24 [ 67.306893] task_work_run+0x104/0x180 [ 67.310846] do_notify_resume+0x458/0x14e0 [ 67.315154] work_pending+0xc/0x5f8 [ 67.318834] [ 67.320429] Allocated by task 2988: [ 67.324105] kasan_save_stack+0x28/0x58 [ 67.328144] kasan_set_track+0x28/0x3c [ 67.332090] ____kasan_kmalloc+0x84/0x9c [ 67.336217] __kasan_kmalloc+0x10/0x1c [ 67.340163] __kmalloc+0x214/0x2f8 [ 67.343754] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 67.349066] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 67.354017] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 67.360705] usb_get_function_instance+0x64/0x68 [libcomposite] [ 67.366934] function_make+0x128/0x1ec [libcomposite] [ 67.372260] configfs_mkdir+0x330/0x590 [configfs] [ 67.377320] vfs_mkdir+0x12c/0x1bc [ 67.380911] do_mkdirat+0x180/0x1d0 [ 67.384589] __arm64_sys_mkdirat+0x80/0x94 [ 67.388899] invoke_syscall+0xf8/0x25c [ 67.392850] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.397969] do_el0_svc+0xa0/0xd4 [ 67.401464] el0_svc+0x24/0x34 [ 67.404691] el0_sync_handler+0xcc/0x154 [ 67.408819] el0_sync+0x198/0x1c0 [ 67.412315] [ 67.413909] Freed by task 2993: [ 67.417220] kasan_save_stack+0x28/0x58 [ 67.421257] kasan_set_track+0x28/0x3c [ 67.425204] kasan_set_free_info+0x28/0x4c [ 67.429513] ____kasan_slab_free+0x104/0x118 [ 67.434001] __kasan_slab_free+0x18/0x24 [ 67.438128] slab_free_freelist_hook+0x148/0x1f0 [ 67.442978] kfree+0x318/0x440 [ 67.446205] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 67.451156] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 67.457385] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 67.462428] config_item_put+0x140/0x1a4 [configfs] [ 67.467570] configfs_rmdir+0x3fc/0x518 [configfs] [ 67.472626] vfs_rmdir+0x114/0x234 [ 67.476215] do_rmdir+0x274/0x2b0 [ 67.479710] __arm64_sys_unlinkat+0x94/0xc8 [ 67.484108] invoke_syscall+0xf8/0x25c [ 67.488055] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.493175] do_el0_svc+0xa0/0xd4 [ 67.496671] el0_svc+0x24/0x34 [ 67.499896] el0_sync_handler+0xcc/0x154 [ 67.504024] el0_sync+0x198/0x1c0 [ 67.507520] [ 67.509114] The buggy address belongs to the object at ffff0004c26e9700 [ 67.509114] which belongs to the cache kmalloc-128 of size 128 [ 67.522171] The buggy address is located 74 bytes inside of [ 67.522171] 128-byte region [ffff0004c26e9700, ffff0004c26e9780) [ 67.534328] The buggy address belongs to the page: [ 67.539355] page:000000003177a217 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5026e8 [ 67.549175] head:000000003177a217 order:1 compound_mapcount:0 [ 67.555195] flags: 0x8000000000010200(slab|head|zone=2) [ 67.560687] raw: 8000000000010200 fffffc0013037100 0000000c00000002 ffff0004c0002300 [ 67.568791] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 [ 67.576890] page dumped because: kasan: bad access detected [ 67.582725] [ 67.584318] Memory state around the buggy address: [ 67.589343] ffff0004c26e9600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.596903] ffff0004c26e9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.604463] >ffff0004c26e9700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.612022] ^ [ 67.617860] ffff0004c26e9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.625421] ffff0004c26e9800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.632981] ================================================================== [ 67.640535] Disabling lock debugging due to kernel taint File descriptor[ 67.646100] Unable to handle kernel paging request at virtual address fabb801d4000018d in bad state [ 67.655456] Mem abort info: [ 67.659619] ESR = 0x96000004 [ 67.662801] EC = 0x25: DABT (current EL), IL = 32 bits [ 67.668225] SET = 0, FnV = 0 [ 67.671375] EA = 0, S1PTW = 0 [ 67.674613] Data abort info: [ 67.677587] ISV = 0, ISS = 0x00000004 [ 67.681522] CM = 0, WnR = 0 [ 67.684588] [fabb801d4000018d] address between user and kernel address ranges [ 67.691849] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 67.697470] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul sha2_ce sha1_ce evdev sata_rcar libata xhci_plat_hcd scsi_mod xhci_hcd rene4 [ 67.740467] CPU: 0 PID: 2994 Comm: cat Tainted: G B 5.13.0-rc4+ #8 [ 67.748005] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.754924] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 67.760974] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.766178] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 67.771365] sp : ffff800014767ad0 [ 67.774706] x29: ffff800014767ad0 x28: ffff800009cf91c0 x27: ffff0004c54861a0 [ 67.781913] x26: ffff0004dc90b288 x25: 1fffe00099ec10f5 x24: 00000000000a801d [ 67.789118] x23: 1fffe00099f6953a x22: dfff800000000000 x21: ffff0004cfb4a9d0 [ 67.796322] x20: d5e000ea00000bb1 x19: ffff0004cfb4a800 x18: 0000000000000000 [ 67.803526] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 67.810730] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000028ecefa [ 67.817934] x11: ffff7000028ecefa x10: 0720072007200720 x9 : ffff80001132c014 [ 67.825137] x8 : ffff8000147677d8 x7 : ffff8000147677d7 x6 : 0000000000000000 [ 67.832341] x5 : 0000000000000001 x4 : ffff7000028ecefb x3 : 0000000000000001 [ 67.839544] x2 : 0000000000000005 x1 : 1abc001d4000018d x0 : d5e000ea00000c6d [ 67.846748] Call trace: [ 67.849218] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.854058] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.858810] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.863736] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.868488] __fput+0x304/0x580 [ 67.871665] ____fput+0x18/0x24 [ 67.874837] task_work_run+0x104/0x180 [ 67.878622] do_notify_resume+0x458/0x14e0 [ 67.882754] work_pending+0xc/0x5f8 [ 67.886282] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 67.892422] ---[ end trace 6d7cedf53d7abbea ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [agabbasov: Backported to earlier mount API, resolved context conflicts] --- drivers/usb/gadget/function/f_fs.c | 67 ++++++++++++++---------------- 1 file changed, 32 insertions(+), 35 deletions(-)
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 458c5dc296ac..5dfe926c251a 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -247,8 +247,8 @@ EXPORT_SYMBOL_GPL(ffs_lock); static struct ffs_dev *_ffs_find_dev(const char *name); static struct ffs_dev *_ffs_alloc_dev(void); static void _ffs_free_dev(struct ffs_dev *dev); -static void *ffs_acquire_dev(const char *dev_name); -static void ffs_release_dev(struct ffs_data *ffs_data); +static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data); +static void ffs_release_dev(struct ffs_dev *ffs_dev); static int ffs_ready(struct ffs_data *ffs); static void ffs_closed(struct ffs_data *ffs);
@@ -1505,7 +1505,6 @@ ffs_fs_mount(struct file_system_type *t, int flags, }; struct dentry *rv; int ret; - void *ffs_dev; struct ffs_data *ffs;
ENTER(); @@ -1526,19 +1525,16 @@ ffs_fs_mount(struct file_system_type *t, int flags, return ERR_PTR(-ENOMEM); }
- ffs_dev = ffs_acquire_dev(dev_name); - if (IS_ERR(ffs_dev)) { + ret = ffs_acquire_dev(dev_name, ffs); + if (ret) { ffs_data_put(ffs); - return ERR_CAST(ffs_dev); + return ERR_PTR(ret); } - ffs->private_data = ffs_dev; data.ffs_data = ffs;
rv = mount_nodev(t, flags, &data, ffs_sb_fill); - if (IS_ERR(rv) && data.ffs_data) { - ffs_release_dev(data.ffs_data); + if (IS_ERR(rv) && data.ffs_data) ffs_data_put(data.ffs_data); - } return rv; }
@@ -1548,10 +1544,8 @@ ffs_fs_kill_sb(struct super_block *sb) ENTER();
kill_litter_super(sb); - if (sb->s_fs_info) { - ffs_release_dev(sb->s_fs_info); + if (sb->s_fs_info) ffs_data_closed(sb->s_fs_info); - } }
static struct file_system_type ffs_fs_type = { @@ -1620,6 +1614,7 @@ static void ffs_data_put(struct ffs_data *ffs) if (unlikely(refcount_dec_and_test(&ffs->ref))) { pr_info("%s(): freeing\n", __func__); ffs_data_clear(ffs); + ffs_release_dev(ffs->private_data); BUG_ON(waitqueue_active(&ffs->ev.waitq) || waitqueue_active(&ffs->ep0req_completion.wait) || waitqueue_active(&ffs->wait)); @@ -2924,6 +2919,7 @@ static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, struct ffs_function *func = ffs_func_from_usb(f); struct f_fs_opts *ffs_opts = container_of(f->fi, struct f_fs_opts, func_inst); + struct ffs_data *ffs_data; int ret;
ENTER(); @@ -2938,12 +2934,13 @@ static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, if (!ffs_opts->no_configfs) ffs_dev_lock(); ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; - func->ffs = ffs_opts->dev->ffs_data; + ffs_data = ffs_opts->dev->ffs_data; if (!ffs_opts->no_configfs) ffs_dev_unlock(); if (ret) return ERR_PTR(ret);
+ func->ffs = ffs_data; func->conf = c; func->gadget = c->cdev->gadget;
@@ -3398,6 +3395,7 @@ static void ffs_free_inst(struct usb_function_instance *f) struct f_fs_opts *opts;
opts = to_f_fs_opts(f); + ffs_release_dev(opts->dev); ffs_dev_lock(); _ffs_free_dev(opts->dev); ffs_dev_unlock(); @@ -3585,47 +3583,48 @@ static void _ffs_free_dev(struct ffs_dev *dev) { list_del(&dev->entry);
- /* Clear the private_data pointer to stop incorrect dev access */ - if (dev->ffs_data) - dev->ffs_data->private_data = NULL; - kfree(dev); if (list_empty(&ffs_devices)) functionfs_cleanup(); }
-static void *ffs_acquire_dev(const char *dev_name) +static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data) { + int ret = 0; struct ffs_dev *ffs_dev;
ENTER(); ffs_dev_lock();
ffs_dev = _ffs_find_dev(dev_name); - if (!ffs_dev) - ffs_dev = ERR_PTR(-ENOENT); - else if (ffs_dev->mounted) - ffs_dev = ERR_PTR(-EBUSY); - else if (ffs_dev->ffs_acquire_dev_callback && - ffs_dev->ffs_acquire_dev_callback(ffs_dev)) - ffs_dev = ERR_PTR(-ENOENT); - else + if (!ffs_dev) { + ret = -ENOENT; + } else if (ffs_dev->mounted) { + ret = -EBUSY; + } else if (ffs_dev->ffs_acquire_dev_callback && + ffs_dev->ffs_acquire_dev_callback(ffs_dev)) { + ret = -ENOENT; + } else { ffs_dev->mounted = true; + ffs_dev->ffs_data = ffs_data; + ffs_data->private_data = ffs_dev; + }
ffs_dev_unlock(); - return ffs_dev; + return ret; }
-static void ffs_release_dev(struct ffs_data *ffs_data) +static void ffs_release_dev(struct ffs_dev *ffs_dev) { - struct ffs_dev *ffs_dev; - ENTER(); ffs_dev_lock();
- ffs_dev = ffs_data->private_data; - if (ffs_dev) { + if (ffs_dev && ffs_dev->mounted) { ffs_dev->mounted = false; + if (ffs_dev->ffs_data) { + ffs_dev->ffs_data->private_data = NULL; + ffs_dev->ffs_data = NULL; + }
if (ffs_dev->ffs_release_dev_callback) ffs_dev->ffs_release_dev_callback(ffs_dev); @@ -3653,7 +3652,6 @@ static int ffs_ready(struct ffs_data *ffs) }
ffs_obj->desc_ready = true; - ffs_obj->ffs_data = ffs;
if (ffs_obj->ffs_ready_callback) { ret = ffs_obj->ffs_ready_callback(ffs); @@ -3681,7 +3679,6 @@ static void ffs_closed(struct ffs_data *ffs) goto done;
ffs_obj->desc_ready = false; - ffs_obj->ffs_data = NULL;
if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && ffs_obj->ffs_closed_callback)
On Sun, Jul 11, 2021 at 10:51:30AM -0500, Andrew Gabbasov wrote:
commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149 upstream.
FunctionFS device structure 'struct ffs_dev' and driver data structure 'struct ffs_data' are bound to each other with cross-reference pointers 'ffs_data->private_data' and 'ffs_dev->ffs_data'. While the first one is supposed to be valid through the whole life of 'struct ffs_data' (and while 'struct ffs_dev' exists non-freed), the second one is cleared in 'ffs_closed()' (called from 'ffs_data_reset()' or the last 'ffs_data_put()'). This can be called several times, alternating in different order with 'ffs_free_inst()', that, if possible, clears the other cross-reference.
As a result, different cases of these calls order may leave stale cross-reference pointers, used when the pointed structure is already freed. Even if it occasionally doesn't cause kernel crash, this error is reported by KASAN-enabled kernel configuration.
For example, the case [last 'ffs_data_put()' - 'ffs_free_inst()'] was fixed by commit cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst").
The other case ['ffs_data_reset()' - 'ffs_free_inst()' - 'ffs_data_put()'] now causes KASAN reported error [1], when 'ffs_data_reset()' clears 'ffs_dev->ffs_data', then 'ffs_free_inst()' frees the 'struct ffs_dev', but can't clear 'ffs_data->private_data', which is then accessed in 'ffs_closed()' called from 'ffs_data_put()'. This happens since 'ffs_dev->ffs_data' reference is cleared too early.
Moreover, one more use case, when 'ffs_free_inst()' is called immediately after mounting FunctionFS device (that is before the descriptors are written and 'ffs_ready()' is called), and then 'ffs_data_reset()' or 'ffs_data_put()' is called from accessing "ep0" file or unmounting the device. This causes KASAN error report like [2], since 'ffs_dev->ffs_data' is not yet set when 'ffs_free_inst()' can't properly clear 'ffs_data->private_data', that is later accessed to freed structure.
Fix these (and may be other) cases of stale pointers access by moving setting and clearing of the mentioned cross-references to the single places, setting both of them when 'struct ffs_data' is created and bound to 'struct ffs_dev', and clearing both of them when one of the structures is destroyed. It seems convenient to make this pointer initialization and structures binding in 'ffs_acquire_dev()' and make pointers clearing in 'ffs_release_dev()'. This required some changes in these functions parameters and return types.
Also, 'ffs_release_dev()' calling requires some cleanup, fixing minor issues, like (1) 'ffs_release_dev()' is not called if 'ffs_free_inst()' is called without unmounting the device, and "release_dev" callback is not called at all, or (2) "release_dev" callback is called before "ffs_closed" callback on unmounting, which seems to be not correctly nested with "acquire_dev" and "ffs_ready" callbacks. Make this cleanup togther with other mentioned 'ffs_release_dev()' changes.
[1]
root@rcar-gen3:~# mkdir /dev/cfs root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 64.340664] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# cd /dev/ffs root@rcar-gen3:/dev/ffs# /home/root/ffs-test ffs-test: info: ep0: writing descriptors (in v2 format) [ 83.181442] read descriptors [ 83.186085] read strings ffs-test: info: ep0: writing strings ffs-test: dbg: ep1: starting ffs-test: dbg: ep2: starting ffs-test: info: ep1: starts ffs-test: info: ep2: starts ffs-test: info: ep0: starts
^C root@rcar-gen3:/dev/ffs# cd /home/root/ root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 98.935061] unloading root@rcar-gen3:~# umount /dev/ffs [ 102.734301] ================================================================== [ 102.742059] BUG: KASAN: use-after-free in ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.749683] Write of size 1 at addr ffff0004d46ff549 by task umount/2997 [ 102.756709] [ 102.758311] CPU: 0 PID: 2997 Comm: umount Not tainted 5.13.0-rc4+ #8 [ 102.764971] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 102.772179] Call trace: [ 102.774779] dump_backtrace+0x0/0x330 [ 102.778653] show_stack+0x20/0x2c [ 102.782152] dump_stack+0x11c/0x1ac [ 102.785833] print_address_description.constprop.0+0x30/0x274 [ 102.791862] kasan_report+0x14c/0x1c8 [ 102.795719] __asan_report_store1_noabort+0x34/0x58 [ 102.800840] ffs_release_dev+0x64/0xa8 [usb_f_fs] [ 102.805801] ffs_fs_kill_sb+0x50/0x84 [usb_f_fs] [ 102.810663] deactivate_locked_super+0xa0/0xf0 [ 102.815339] deactivate_super+0x98/0xac [ 102.819378] cleanup_mnt+0xd0/0x1b0 [ 102.823057] __cleanup_mnt+0x1c/0x28 [ 102.826823] task_work_run+0x104/0x180 [ 102.830774] do_notify_resume+0x458/0x14e0 [ 102.835083] work_pending+0xc/0x5f8 [ 102.838762] [ 102.840357] Allocated by task 2988: [ 102.844032] kasan_save_stack+0x28/0x58 [ 102.848071] kasan_set_track+0x28/0x3c [ 102.852016] ____kasan_kmalloc+0x84/0x9c [ 102.856142] __kasan_kmalloc+0x10/0x1c [ 102.860088] __kmalloc+0x214/0x2f8 [ 102.863678] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 102.868990] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 102.873942] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 102.880629] usb_get_function_instance+0x64/0x68 [libcomposite] [ 102.886858] function_make+0x128/0x1ec [libcomposite] [ 102.892185] configfs_mkdir+0x330/0x590 [configfs] [ 102.897245] vfs_mkdir+0x12c/0x1bc [ 102.900835] do_mkdirat+0x180/0x1d0 [ 102.904513] __arm64_sys_mkdirat+0x80/0x94 [ 102.908822] invoke_syscall+0xf8/0x25c [ 102.912772] el0_svc_common.constprop.0+0x150/0x1a0 [ 102.917891] do_el0_svc+0xa0/0xd4 [ 102.921386] el0_svc+0x24/0x34 [ 102.924613] el0_sync_handler+0xcc/0x154 [ 102.928743] el0_sync+0x198/0x1c0 [ 102.932238] [ 102.933832] Freed by task 2996: [ 102.937144] kasan_save_stack+0x28/0x58 [ 102.941181] kasan_set_track+0x28/0x3c [ 102.945128] kasan_set_free_info+0x28/0x4c [ 102.949435] ____kasan_slab_free+0x104/0x118 [ 102.953921] __kasan_slab_free+0x18/0x24 [ 102.958047] slab_free_freelist_hook+0x148/0x1f0 [ 102.962897] kfree+0x318/0x440 [ 102.966123] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 102.971075] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 102.977302] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 102.982344] config_item_put+0x140/0x1a4 [configfs] [ 102.987486] configfs_rmdir+0x3fc/0x518 [configfs] [ 102.992535] vfs_rmdir+0x114/0x234 [ 102.996122] do_rmdir+0x274/0x2b0 [ 102.999617] __arm64_sys_unlinkat+0x94/0xc8 [ 103.004015] invoke_syscall+0xf8/0x25c [ 103.007961] el0_svc_common.constprop.0+0x150/0x1a0 [ 103.013080] do_el0_svc+0xa0/0xd4 [ 103.016575] el0_svc+0x24/0x34 [ 103.019801] el0_sync_handler+0xcc/0x154 [ 103.023930] el0_sync+0x198/0x1c0 [ 103.027426] [ 103.029020] The buggy address belongs to the object at ffff0004d46ff500 [ 103.029020] which belongs to the cache kmalloc-128 of size 128 [ 103.042079] The buggy address is located 73 bytes inside of [ 103.042079] 128-byte region [ffff0004d46ff500, ffff0004d46ff580) [ 103.054236] The buggy address belongs to the page: [ 103.059262] page:0000000021aa849b refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0004d46fee00 pfn:0x5146fe [ 103.070437] head:0000000021aa849b order:1 compound_mapcount:0 [ 103.076456] flags: 0x8000000000010200(slab|head|zone=2) [ 103.081948] raw: 8000000000010200 fffffc0013521a80 0000000d0000000d ffff0004c0002300 [ 103.090052] raw: ffff0004d46fee00 000000008020001e 00000001ffffffff 0000000000000000 [ 103.098150] page dumped because: kasan: bad access detected [ 103.103985] [ 103.105578] Memory state around the buggy address: [ 103.110602] ffff0004d46ff400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.118161] ffff0004d46ff480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.125726] >ffff0004d46ff500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.133284] ^ [ 103.139120] ffff0004d46ff580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 103.146679] ffff0004d46ff600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 103.154238] ================================================================== [ 103.161792] Disabling lock debugging due to kernel taint [ 103.167319] Unable to handle kernel paging request at virtual address 0037801d6000018e [ 103.175406] Mem abort info: [ 103.178457] ESR = 0x96000004 [ 103.181609] EC = 0x25: DABT (current EL), IL = 32 bits [ 103.187020] SET = 0, FnV = 0 [ 103.190185] EA = 0, S1PTW = 0 [ 103.193417] Data abort info: [ 103.196385] ISV = 0, ISS = 0x00000004 [ 103.200315] CM = 0, WnR = 0 [ 103.203366] [0037801d6000018e] address between user and kernel address ranges [ 103.210611] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 103.216231] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk sata_rc4 [ 103.259233] CPU: 0 PID: 2997 Comm: umount Tainted: G B 5.13.0-rc4+ #8 [ 103.267031] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 103.273951] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 103.280001] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.285197] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 103.290385] sp : ffff800014777a80 [ 103.293725] x29: ffff800014777a80 x28: ffff0004d7649c80 x27: 0000000000000000 [ 103.300931] x26: ffff800014777fb0 x25: ffff60009aec9394 x24: ffff0004d7649ca4 [ 103.308136] x23: 1fffe0009a3d063a x22: dfff800000000000 x21: ffff0004d1e831d0 [ 103.315340] x20: e1c000eb00000bb4 x19: ffff0004d1e83000 x18: 0000000000000000 [ 103.322545] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 103.329748] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000012ef658 [ 103.336952] x11: ffff7000012ef658 x10: 0720072007200720 x9 : ffff800011322648 [ 103.344157] x8 : ffff800014777818 x7 : ffff80000977b2c7 x6 : 0000000000000000 [ 103.351359] x5 : 0000000000000001 x4 : ffff7000012ef659 x3 : 0000000000000001 [ 103.358562] x2 : 0000000000000000 x1 : 1c38001d6000018e x0 : e1c000eb00000c70 [ 103.365766] Call trace: [ 103.368235] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 103.373076] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 103.377829] ffs_data_closed+0x1ec/0x244 [usb_f_fs] [ 103.382755] ffs_fs_kill_sb+0x70/0x84 [usb_f_fs] [ 103.387420] deactivate_locked_super+0xa0/0xf0 [ 103.391905] deactivate_super+0x98/0xac [ 103.395776] cleanup_mnt+0xd0/0x1b0 [ 103.399299] __cleanup_mnt+0x1c/0x28 [ 103.402906] task_work_run+0x104/0x180 [ 103.406691] do_notify_resume+0x458/0x14e0 [ 103.410823] work_pending+0xc/0x5f8 [ 103.414351] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 103.420490] ---[ end trace 57b43a50e8244f57 ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
[2]
root@rcar-gen3:~# mkdir /dev/ffs root@rcar-gen3:~# modprobe libcomposite root@rcar-gen3:~# root@rcar-gen3:~# mount -t configfs none /dev/cfs root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1 root@rcar-gen3:~# mkdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 54.766480] file system registered root@rcar-gen3:~# mount -t functionfs ffs /dev/ffs root@rcar-gen3:~# rmdir /dev/cfs/usb_gadget/g1/functions/ffs.ffs [ 63.197597] unloading root@rcar-gen3:~# cat /dev/ffs/ep0 cat: read error:[ 67.213506] ================================================================== [ 67.222095] BUG: KASAN: use-after-free in ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.229699] Write of size 1 at addr ffff0004c26e974a by task cat/2994 [ 67.236446] [ 67.238045] CPU: 0 PID: 2994 Comm: cat Not tainted 5.13.0-rc4+ #8 [ 67.244431] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.251624] Call trace: [ 67.254212] dump_backtrace+0x0/0x330 [ 67.258081] show_stack+0x20/0x2c [ 67.261579] dump_stack+0x11c/0x1ac [ 67.265260] print_address_description.constprop.0+0x30/0x274 [ 67.271286] kasan_report+0x14c/0x1c8 [ 67.275143] __asan_report_store1_noabort+0x34/0x58 [ 67.280265] ffs_data_clear+0x70/0x370 [usb_f_fs] [ 67.285220] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.290172] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.295305] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.300256] __fput+0x304/0x580 [ 67.303576] ____fput+0x18/0x24 [ 67.306893] task_work_run+0x104/0x180 [ 67.310846] do_notify_resume+0x458/0x14e0 [ 67.315154] work_pending+0xc/0x5f8 [ 67.318834] [ 67.320429] Allocated by task 2988: [ 67.324105] kasan_save_stack+0x28/0x58 [ 67.328144] kasan_set_track+0x28/0x3c [ 67.332090] ____kasan_kmalloc+0x84/0x9c [ 67.336217] __kasan_kmalloc+0x10/0x1c [ 67.340163] __kmalloc+0x214/0x2f8 [ 67.343754] kzalloc.constprop.0+0x14/0x20 [usb_f_fs] [ 67.349066] ffs_alloc_inst+0x8c/0x208 [usb_f_fs] [ 67.354017] try_get_usb_function_instance+0xf0/0x164 [libcomposite] [ 67.360705] usb_get_function_instance+0x64/0x68 [libcomposite] [ 67.366934] function_make+0x128/0x1ec [libcomposite] [ 67.372260] configfs_mkdir+0x330/0x590 [configfs] [ 67.377320] vfs_mkdir+0x12c/0x1bc [ 67.380911] do_mkdirat+0x180/0x1d0 [ 67.384589] __arm64_sys_mkdirat+0x80/0x94 [ 67.388899] invoke_syscall+0xf8/0x25c [ 67.392850] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.397969] do_el0_svc+0xa0/0xd4 [ 67.401464] el0_svc+0x24/0x34 [ 67.404691] el0_sync_handler+0xcc/0x154 [ 67.408819] el0_sync+0x198/0x1c0 [ 67.412315] [ 67.413909] Freed by task 2993: [ 67.417220] kasan_save_stack+0x28/0x58 [ 67.421257] kasan_set_track+0x28/0x3c [ 67.425204] kasan_set_free_info+0x28/0x4c [ 67.429513] ____kasan_slab_free+0x104/0x118 [ 67.434001] __kasan_slab_free+0x18/0x24 [ 67.438128] slab_free_freelist_hook+0x148/0x1f0 [ 67.442978] kfree+0x318/0x440 [ 67.446205] ffs_free_inst+0x164/0x2d8 [usb_f_fs] [ 67.451156] usb_put_function_instance+0x84/0xa4 [libcomposite] [ 67.457385] ffs_attr_release+0x18/0x24 [usb_f_fs] [ 67.462428] config_item_put+0x140/0x1a4 [configfs] [ 67.467570] configfs_rmdir+0x3fc/0x518 [configfs] [ 67.472626] vfs_rmdir+0x114/0x234 [ 67.476215] do_rmdir+0x274/0x2b0 [ 67.479710] __arm64_sys_unlinkat+0x94/0xc8 [ 67.484108] invoke_syscall+0xf8/0x25c [ 67.488055] el0_svc_common.constprop.0+0x150/0x1a0 [ 67.493175] do_el0_svc+0xa0/0xd4 [ 67.496671] el0_svc+0x24/0x34 [ 67.499896] el0_sync_handler+0xcc/0x154 [ 67.504024] el0_sync+0x198/0x1c0 [ 67.507520] [ 67.509114] The buggy address belongs to the object at ffff0004c26e9700 [ 67.509114] which belongs to the cache kmalloc-128 of size 128 [ 67.522171] The buggy address is located 74 bytes inside of [ 67.522171] 128-byte region [ffff0004c26e9700, ffff0004c26e9780) [ 67.534328] The buggy address belongs to the page: [ 67.539355] page:000000003177a217 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5026e8 [ 67.549175] head:000000003177a217 order:1 compound_mapcount:0 [ 67.555195] flags: 0x8000000000010200(slab|head|zone=2) [ 67.560687] raw: 8000000000010200 fffffc0013037100 0000000c00000002 ffff0004c0002300 [ 67.568791] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 [ 67.576890] page dumped because: kasan: bad access detected [ 67.582725] [ 67.584318] Memory state around the buggy address: [ 67.589343] ffff0004c26e9600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.596903] ffff0004c26e9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.604463] >ffff0004c26e9700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.612022] ^ [ 67.617860] ffff0004c26e9780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.625421] ffff0004c26e9800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 67.632981] ================================================================== [ 67.640535] Disabling lock debugging due to kernel taint File descriptor[ 67.646100] Unable to handle kernel paging request at virtual address fabb801d4000018d in bad state [ 67.655456] Mem abort info: [ 67.659619] ESR = 0x96000004 [ 67.662801] EC = 0x25: DABT (current EL), IL = 32 bits [ 67.668225] SET = 0, FnV = 0 [ 67.671375] EA = 0, S1PTW = 0 [ 67.674613] Data abort info: [ 67.677587] ISV = 0, ISS = 0x00000004 [ 67.681522] CM = 0, WnR = 0 [ 67.684588] [fabb801d4000018d] address between user and kernel address ranges [ 67.691849] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 67.697470] Modules linked in: usb_f_fs libcomposite configfs ath9k_htc led_class mac80211 libarc4 ath9k_common ath9k_hw ath cfg80211 aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul sha2_ce sha1_ce evdev sata_rcar libata xhci_plat_hcd scsi_mod xhci_hcd rene4 [ 67.740467] CPU: 0 PID: 2994 Comm: cat Tainted: G B 5.13.0-rc4+ #8 [ 67.748005] Hardware name: Renesas Salvator-X board based on r8a77951 (DT) [ 67.754924] pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) [ 67.760974] pc : ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.766178] lr : ffs_data_clear+0x124/0x370 [usb_f_fs] [ 67.771365] sp : ffff800014767ad0 [ 67.774706] x29: ffff800014767ad0 x28: ffff800009cf91c0 x27: ffff0004c54861a0 [ 67.781913] x26: ffff0004dc90b288 x25: 1fffe00099ec10f5 x24: 00000000000a801d [ 67.789118] x23: 1fffe00099f6953a x22: dfff800000000000 x21: ffff0004cfb4a9d0 [ 67.796322] x20: d5e000ea00000bb1 x19: ffff0004cfb4a800 x18: 0000000000000000 [ 67.803526] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 67.810730] x14: 0720072007200720 x13: 0720072007200720 x12: 1ffff000028ecefa [ 67.817934] x11: ffff7000028ecefa x10: 0720072007200720 x9 : ffff80001132c014 [ 67.825137] x8 : ffff8000147677d8 x7 : ffff8000147677d7 x6 : 0000000000000000 [ 67.832341] x5 : 0000000000000001 x4 : ffff7000028ecefb x3 : 0000000000000001 [ 67.839544] x2 : 0000000000000005 x1 : 1abc001d4000018d x0 : d5e000ea00000c6d [ 67.846748] Call trace: [ 67.849218] ffs_data_clear+0x138/0x370 [usb_f_fs] [ 67.854058] ffs_data_reset+0x20/0x304 [usb_f_fs] [ 67.858810] ffs_data_closed+0x240/0x244 [usb_f_fs] [ 67.863736] ffs_ep0_release+0x40/0x54 [usb_f_fs] [ 67.868488] __fput+0x304/0x580 [ 67.871665] ____fput+0x18/0x24 [ 67.874837] task_work_run+0x104/0x180 [ 67.878622] do_notify_resume+0x458/0x14e0 [ 67.882754] work_pending+0xc/0x5f8 [ 67.886282] Code: b4000a54 9102f280 12000802 d343fc01 (38f66821) [ 67.892422] ---[ end trace 6d7cedf53d7abbea ]--- Segmentation fault root@rcar-gen3:~# ==================================================================
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [agabbasov: Backported to earlier mount API, resolved context conflicts]
drivers/usb/gadget/function/f_fs.c | 67 ++++++++++++++---------------- 1 file changed, 32 insertions(+), 35 deletions(-)
I also need a 4.19 version of this commit, as you do not want to upgrade to a newer kernel and regress. Can you also provide that?
thanks,
greg k-h
Hello Greg,
-----Original Message----- From: Greg Kroah-Hartman gregkh@linuxfoundation.org Sent: Sunday, July 11, 2021 7:07 PM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Sun, Jul 11, 2021 at 10:51:30AM -0500, Andrew Gabbasov wrote:
commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149 upstream.
[ skipped ]
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [agabbasov: Backported to earlier mount API, resolved context conflicts]
drivers/usb/gadget/function/f_fs.c | 67 ++++++++++++++---------------- 1 file changed, 32 insertions(+), 35 deletions(-)
I also need a 4.19 version of this commit, as you do not want to upgrade to a newer kernel and regress. Can you also provide that?
If I correctly understand, this particular file has a very minor difference between 4.14 and 4.19. So, this same patch for 4.14 can be just applied / cherry-picked cleanly on top of latest stable 4.19.
Thanks!
Best regards, Andrew
On Sun, Jul 11, 2021 at 07:44:41PM +0300, Andrew Gabbasov wrote:
Hello Greg,
-----Original Message----- From: Greg Kroah-Hartman gregkh@linuxfoundation.org Sent: Sunday, July 11, 2021 7:07 PM To: Gabbasov, Andrew Andrew_Gabbasov@mentor.com Cc: Macpaul Lin macpaul.lin@mediatek.com; Eugeniu Rosca erosca@de.adit-jv.com; linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; stable@vger.kernel.org; Felipe Balbi balbi@kernel.org; Eugeniu Rosca roscaeugeniu@gmail.com; Eddie Hung eddie.hung@mediatek.com Subject: Re: [PATCH v4.14] usb: gadget: f_fs: Fix setting of device and driver data cross-references
On Sun, Jul 11, 2021 at 10:51:30AM -0500, Andrew Gabbasov wrote:
commit ecfbd7b9054bddb12cea07fda41bb3a79a7b0149 upstream.
[ skipped ]
Fixes: 4b187fceec3c ("usb: gadget: FunctionFS: add devices management code") Fixes: 3262ad824307 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference") Fixes: cdafb6d8b8da ("usb: gadget: f_fs: Fix use-after-free in ffs_free_inst") Reported-by: Bhuvanesh Surachari bhuvanesh_surachari@mentor.com Tested-by: Eugeniu Rosca erosca@de.adit-jv.com Reviewed-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: Andrew Gabbasov andrew_gabbasov@mentor.com Link: https://lore.kernel.org/r/20210603171507.22514-1-andrew_gabbasov@mentor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [agabbasov: Backported to earlier mount API, resolved context conflicts]
drivers/usb/gadget/function/f_fs.c | 67 ++++++++++++++---------------- 1 file changed, 32 insertions(+), 35 deletions(-)
I also need a 4.19 version of this commit, as you do not want to upgrade to a newer kernel and regress. Can you also provide that?
If I correctly understand, this particular file has a very minor difference between 4.14 and 4.19. So, this same patch for 4.14 can be just applied / cherry-picked cleanly on top of latest stable 4.19.
Now queued up, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
'Greg Kroah-Hartman' -
Andrew Gabbasov -
Greg Kroah-Hartman
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Macpaul Lin