CVE-2022-49321: xprtrdma: treat all calls not a bcall when bc_serv is NULL

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-08-04
Weakness: CWE-476

Description

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 ...

Affected products

Linux kernel: before 4.14.283; from 4.15 before 4.19.247; from 4.20 before 5.4.198; from 5.5 before 5.10.122; from 5.11 before 5.15.47; from 5.16 before 5.17.15 — fixed in 4.14.283, 4.19.247, 5.10.122, 5.15.47, 5.17.15, 5.18.4

How to fix

Upgrade to a fixed version: Linux kernel 4.14.283, 4.19.247, 5.10.122, 5.15.47. Check the vendor advisory for mitigations.

References

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