From: Wentao_Liang Wentao_Liang_g@163.com
[ Upstream commit 8fc74d18639a2402ca52b177e990428e26ea881f ]
The pointer vdev points to a memory region adjacent to a net_device structure ndev, which is a field of hldev. At line 4740, the invocation to vxge_device_unregister unregisters device hldev, and it also releases the memory region pointed by vdev->bar0. At line 4743, the freed memory region is referenced (i.e., iounmap(vdev->bar0)), resulting in a use-after-free vulnerability. We can fix the bug by calling iounmap before vxge_device_unregister.
4721. static void vxge_remove(struct pci_dev *pdev) 4722. { 4723. struct __vxge_hw_device *hldev; 4724. struct vxgedev *vdev; … 4731. vdev = netdev_priv(hldev->ndev); … 4740. vxge_device_unregister(hldev); 4741. /* Do not call pci_disable_sriov here, as it will break child devices */ 4742. vxge_hw_device_terminate(hldev); 4743. iounmap(vdev->bar0); … 4749 vxge_debug_init(vdev->level_trace, "%s:%d Device unregistered", 4750 __func__, __LINE__); 4751 vxge_debug_entryexit(vdev->level_trace, "%s:%d Exiting...", __func__, 4752 __LINE__); 4753. }
This is the screenshot when the vulnerability is triggered by using KASAN. We can see that there is a use-after-free reported by KASAN.
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root@kernel:~# echo 1 > /sys/bus/pci/devices/0000:00:03.0/remove [ 178.296316] vxge_remove [ 182.057081] ================================================================== [ 182.057548] BUG: KASAN: use-after-free in vxge_remove+0xe0/0x15c [ 182.057760] Read of size 8 at addr ffff888006c76598 by task bash/119 [ 182.057983] [ 182.058747] CPU: 0 PID: 119 Comm: bash Not tainted 5.18.0 #5 [ 182.058919] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 182.059463] Call Trace: [ 182.059726] <TASK> [ 182.060017] dump_stack_lvl+0x34/0x44 [ 182.060316] print_report.cold+0xb2/0x6b7 [ 182.060401] ? kfree+0x89/0x290 [ 182.060478] ? vxge_remove+0xe0/0x15c [ 182.060545] kasan_report+0xa9/0x120 [ 182.060629] ? vxge_remove+0xe0/0x15c [ 182.060706] vxge_remove+0xe0/0x15c [ 182.060793] pci_device_remove+0x5d/0xe0 [ 182.060968] device_release_driver_internal+0xf1/0x180 [ 182.061063] pci_stop_bus_device+0xae/0xe0 [ 182.061150] pci_stop_and_remove_bus_device_locked+0x11/0x20 [ 182.061236] remove_store+0xc6/0xe0 [ 182.061297] ? subordinate_bus_number_show+0xc0/0xc0 [ 182.061359] ? __mutex_lock_slowpath+0x10/0x10 [ 182.061438] ? sysfs_kf_write+0x6d/0xa0 [ 182.061525] kernfs_fop_write_iter+0x1b0/0x260 [ 182.061610] ? sysfs_kf_bin_read+0xf0/0xf0 [ 182.061695] new_sync_write+0x209/0x310 [ 182.061789] ? new_sync_read+0x310/0x310 [ 182.061865] ? cgroup_rstat_updated+0x5c/0x170 [ 182.061937] ? preempt_count_sub+0xf/0xb0 [ 182.061995] ? pick_next_entity+0x13a/0x220 [ 182.062063] ? __inode_security_revalidate+0x44/0x80 [ 182.062155] ? security_file_permission+0x46/0x2a0 [ 182.062230] vfs_write+0x33f/0x3e0 [ 182.062303] ksys_write+0xb4/0x150 [ 182.062369] ? __ia32_sys_read+0x40/0x40 [ 182.062451] do_syscall_64+0x3b/0x90 [ 182.062531] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [ 182.062894] RIP: 0033:0x7f3f37d17274 [ 182.063558] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 48 8d 05 89 54 0d 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 49 89 d4 55 48 89 f5 53 [ 182.063797] RSP: 002b:00007ffd5ba9e178 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 182.064117] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f3f37d17274 [ 182.064219] RDX: 0000000000000002 RSI: 000055bbec327180 RDI: 0000000000000001 [ 182.064315] RBP: 000055bbec327180 R08: 000000000000000a R09: 00007f3f37de7cf0 [ 182.064414] R10: 000000000000000a R11: 0000000000000246 R12: 00007f3f37de8760 [ 182.064513] R13: 0000000000000002 R14: 00007f3f37de3760 R15: 0000000000000002 [ 182.064691] </TASK> [ 182.064916] [ 182.065224] The buggy address belongs to the physical page: [ 182.065804] page:00000000ef31e4f4 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6c76 [ 182.067419] flags: 0x100000000000000(node=0|zone=1) [ 182.068997] raw: 0100000000000000 0000000000000000 ffffea00001b1d88 0000000000000000 [ 182.069118] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 182.069294] page dumped because: kasan: bad access detected [ 182.069331] [ 182.069360] Memory state around the buggy address: [ 182.070006] ffff888006c76480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 182.070136] ffff888006c76500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 182.070230] >ffff888006c76580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 182.070305] ^ [ 182.070456] ffff888006c76600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 182.070505] ffff888006c76680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 182.070606] ================================================================== [ 182.071374] Disabling lock debugging due to kernel taint
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After fixing the bug as done in the patch, we can find KASAN do not report the bug and the device(00:03.0) has been successfully removed.
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root@kernel:~# echo 1 > /sys/bus/pci/devices/0000:00:03.0/remove root@kernel:~#
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Signed-off-by: Wentao_Liang Wentao_Liang_g@163.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/neterion/vxge/vxge-main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/neterion/vxge/vxge-main.c b/drivers/net/ethernet/neterion/vxge/vxge-main.c index df4a3f3da83a..6bbda3676c1a 100644 --- a/drivers/net/ethernet/neterion/vxge/vxge-main.c +++ b/drivers/net/ethernet/neterion/vxge/vxge-main.c @@ -4760,10 +4760,10 @@ static void vxge_remove(struct pci_dev *pdev) for (i = 0; i < vdev->no_of_vpath; i++) vxge_free_mac_add_list(&vdev->vpaths[i]);
+ iounmap(vdev->bar0); vxge_device_unregister(hldev); /* Do not call pci_disable_sriov here, as it will break child devices */ vxge_hw_device_terminate(hldev); - iounmap(vdev->bar0); pci_release_region(pdev, 0); pci_disable_device(pdev); driver_config->config_dev_cnt--;