CVE-2021-47212 net/mlx5: Update error handler for UCTX and UMEM
A flaw in the Linux kernel mlx5 driver causes a call trace and potential crash during device unbinding, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47212?
CVE-2021-47212 is a medium-severity denial of service vulnerability in Linux kernel, published on 10 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Update error handler for UCTX and UMEM
In the fast unload flow, the device state is set to internal error, which indicates that the driver started the destroy process. In this case, when a destroy command is being executed, it should return MLX5_CMD_STAT_OK. Fix MLX5_CMD_OP_DESTROY_UCTX and MLX5_CMD_OP_DESTROY_UMEM to return OK instead of EIO.
This fixes a call trace in the umem release process - [ 2633.536695] Call Trace: [ 2633.537518] ib_uverbs_remove_one+0xc3/0x140 [ib_uverbs] [ 2633.538596] remove_client_context+0x8b/0xd0 [ib_core] [ 2633.539641] disable_device+0x8c/0x130 [ib_core] [ 2633.540615] __ib_unregister_device+0x35/0xa0 [ib_core] [ 2633.541640] ib_unregister_device+0x21/0x30 [ib_core] [ 2633.542663] __mlx5_ib_remove+0x38/0x90 [mlx5_ib] [ 2633.543640] auxiliary_bus_remove+0x1e/0x30 [auxiliary] [ 2633.544661] device_release_driver_internal+0x103/0x1f0 [ 2633.545679] bus_remove_device+0xf7/0x170 [ 2633.546640] device_del+0x181/0x410 [ 2633.547606] mlx5_rescan_drivers_locked.part.10+0x63/0x160 [mlx5_core] [ 2633.548777] mlx5_unregister_device+0x27/0x40 [mlx5_core] [ 2633.549841] mlx5_uninit_one+0x21/0xc0 [mlx5_core] [ 2633.550864] remove_one+0x69/0xe0 [mlx5_core] [ 2633.551819] pci_device_remove+0x3b/0xc0 [ 2633.552731] device_release_driver_internal+0x103/0x1f0 [ 2633.553746] unbind_store+0xf6/0x130 [ 2633.554657] kernfs_fop_write+0x116/0x190 [ 2633.555567] vfs_write+0xa5/0x1a0 [ 2633.556407] ksys_write+0x4f/0xb0 [ 2633.557233] do_syscall_64+0x5b/0x1a0 [ 2633.558071] entry_SYSCALL_64_after_hwframe+0x65/0xca [ 2633.559018] RIP: 0033:0x7f9977132648 [ 2633.559821] Code: 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 55 6f 2d 00 8b 00 85 c0 75 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 49 89 d4 55 [ 2633.562332] RSP: 002b:00007fffb1a83888 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 2633.563472] RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f9977132648 [ 2633.564541] RDX: 000000000000000c RSI: 000055b90546e230 RDI: 0000000000000001 [ 2633.565596] RBP: 000055b90546e230 R08: 00007f9977406860 R09: 00007f9977a54740 [ 2633.566653] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f99774056e0 [ 2633.567692] R13: 000000000000000c R14: 00007f9977400880 R15: 000000000000000c [ 2633.568725] ---[ end trace 10b4fe52945e544d ]---
Which versions are affected by CVE-2021-47212?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47212?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-47212 being exploited?
There is no known exploitation of CVE-2021-47212 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47212, GHSA-9w6w-gqmh-gxp9, ROOT-OS-DEBIAN-11-CVE-2021-47212, UBUNTU-CVE-2021-47212.