From: YueHaibing yuehaibing@huawei.com
commit 56cd26b618855c9af48c8301aa6754ced8dd0beb upstream.
Syzkaller report this:
BUG: KASAN: use-after-free in sysfs_remove_file_ns+0x5f/0x70 fs/sysfs/file.c:468 Read of size 8 at addr ffff8881dc7ae030 by task syz-executor.0/6249
CPU: 1 PID: 6249 Comm: syz-executor.0 Not tainted 5.0.0-rc8+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xfa/0x1ce lib/dump_stack.c:113 print_address_description+0x65/0x270 mm/kasan/report.c:187 kasan_report+0x149/0x18d mm/kasan/report.c:317 ? 0xffffffffc1728000 sysfs_remove_file_ns+0x5f/0x70 fs/sysfs/file.c:468 sysfs_remove_file include/linux/sysfs.h:519 [inline] driver_remove_file+0x40/0x50 drivers/base/driver.c:122 remove_bind_files drivers/base/bus.c:585 [inline] bus_remove_driver+0x186/0x220 drivers/base/bus.c:725 driver_unregister+0x6c/0xa0 drivers/base/driver.c:197 serial_ir_init_module+0x169/0x1000 [serial_ir] do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9450132c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007f9450132c70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f94501336bc R13: 00000000004bcefa R14: 00000000006f6fb0 R15: 0000000000000004
Allocated by task 6249: set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:495 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] bus_add_driver+0xc0/0x610 drivers/base/bus.c:651 driver_register+0x1bb/0x3f0 drivers/base/driver.c:170 serial_ir_init_module+0xe8/0x1000 [serial_ir] do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 6249: set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:457 slab_free_hook mm/slub.c:1430 [inline] slab_free_freelist_hook mm/slub.c:1457 [inline] slab_free mm/slub.c:3005 [inline] kfree+0xe1/0x270 mm/slub.c:3957 kobject_cleanup lib/kobject.c:662 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:67 [inline] kobject_put+0x146/0x240 lib/kobject.c:708 bus_remove_driver+0x10e/0x220 drivers/base/bus.c:732 driver_unregister+0x6c/0xa0 drivers/base/driver.c:197 serial_ir_init_module+0x14c/0x1000 [serial_ir] do_one_initcall+0xfa/0x5ca init/main.c:887 do_init_module+0x204/0x5f6 kernel/module.c:3460 load_module+0x66b2/0x8570 kernel/module.c:3808 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8881dc7ae000 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of 256-byte region [ffff8881dc7ae000, ffff8881dc7ae100) The buggy address belongs to the page: page:ffffea000771eb80 count:1 mapcount:0 mapping:ffff8881f6c02e00 index:0x0 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0007d14800 0000000400000002 ffff8881f6c02e00 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8881dc7adf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881dc7adf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881dc7ae000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff8881dc7ae080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881dc7ae100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
There are already cleanup handlings in serial_ir_init error path, no need to call serial_ir_exit do it again in serial_ir_init_module, otherwise will trigger a use-after-free issue.
Fixes: fa5dc29c1fcc ("[media] lirc_serial: move out of staging and rename to serial_ir")
Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: YueHaibing yuehaibing@huawei.com Signed-off-by: Sean Young sean@mess.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/rc/serial_ir.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-)
--- a/drivers/media/rc/serial_ir.c +++ b/drivers/media/rc/serial_ir.c @@ -774,8 +774,6 @@ static void serial_ir_exit(void)
static int __init serial_ir_init_module(void) { - int result; - switch (type) { case IR_HOMEBREW: case IR_IRDEO: @@ -803,12 +801,7 @@ static int __init serial_ir_init_module( if (sense != -1) sense = !!sense;
- result = serial_ir_init(); - if (!result) - return 0; - - serial_ir_exit(); - return result; + return serial_ir_init(); }
static void __exit serial_ir_exit_module(void)