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7.5

Linux Kernel: Unhandled NFS Call Can Crash Server

CVE-2022-49321 · published 1 year ago
Summary

A bug in the Linux kernel's NFS (file sharing) feature can cause a server to crash if a certain type of error message is received from a remote server. This bug has been fixed, and users should update their Linux kernel to the latest version to prevent potential crashes. If you're running a Linux server, check with your vendor for an update to ensure your system is protected.

What to do
  • Update linux linux to version 8e3943c50764dc7c5f25911970c3ff062ec1f18c or later.
Affected software
VendorProductAffected versions
linux linux_kernel < 4.14.283
>= 4.15, < 4.19.247
>= 4.20, < 5.4.198
>= 5.5, < 5.10.122
>= 5.11, < 5.15.47
>= 5.16, < 5.17.15
>= 5.18, < 5.18.4
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux < 8e3943c50764dc7c5f25911970c3ff062ec1f18c
4.4
Original advisory text
xprtrdma: treat all calls not a bcall when bc_serv is NULL
In the Linux kernel, the following vulnerability has been resolved:

xprtrdma: treat all calls not a bcall when bc_serv is NULL

When a rdma server returns a fault format reply, nfs v3 client may
treats it as a bcall when bc service is not exist.

The debug message at rpcrdma_bc_receive_call are,

[56579.837169] RPC: rpcrdma_bc_receive_call: callback XID
00000001, length=20
[56579.837174] RPC: rpcrdma_bc_receive_call: 00 00 00 01 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 04

After that, rpcrdma_bc_receive_call will meets NULL pointer as,

[ 226.057890] BUG: unable to handle kernel NULL pointer dereference at
00000000000000c8
...
[ 226.058704] RIP: 0010:_raw_spin_lock+0xc/0x20
...
[ 226.059732] Call Trace:
[ 226.059878] rpcrdma_bc_receive_call+0x138/0x327 [rpcrdma]
[ 226.060011] __ib_process_cq+0x89/0x170 [ib_core]
[ 226.060092] ib_cq_poll_work+0x26/0x80 [ib_core]
[ 226.060257] process_one_work+0x1a7/0x360
[ 226.060367] ? create_worker+0x1a0/0x1a0
[ 226.060440] worker_thread+0x30/0x390
[ 226.060500] ? create_worker+0x1a0/0x1a0
[ 226.060574] kthread+0x116/0x130
[ 226.060661] ? kthread_flush_work_fn+0x10/0x10
[ 226.060724] ret_from_fork+0x35/0x40
...
References
Severity
7.5 High
CVSS 3.1: 5.5 (NVD)
Exploitation
EPSS <1%
Type
CWE-476NULL Pointer Dereference
Timeline
Published26 Feb 2025
Updated15 Aug 2026
First seen7 Mar 2026
Sources
CVE-2022-49321 · NVD
CVE-2022-49321 · MITRE
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