CVE-2022-49065: SUNRPC: Fix the svc_deferred_event trace class

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% 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: SUNRPC: Fix the svc_deferred_event trace class Fix a NULL deref crash that occurs when an svc_rqst is deferred while the sunrpc tracing subsystem is enabled. svc_revisit() sets dr->xprt to NULL, so it can't be relied upon in the tracepoint to provide the remote's address. Unfortunately we can't revert the "svc_deferred_class" hunk in commit ece200ddd54b ("sunrpc: Save remote presentation address in svc_xprt for trace events") because there is now a specific check of event format specifiers for unsafe dereferences. The warning that check emits is: event svc_defer_recv has unsafe dereference of argument 1 A "%pISpc" format specifier with a "struct sockaddr *" is indeed flagged by this check. Instead, take the brute-force approach used by the svcrdma_qp_error tracepoint. Convert the dr::addr field into a presentation address in the TP_fast_assign() arm of the trace event, and store that as a string. This fix can be backported to -stable kernels. In the meantime, commit c6ced22997ad ("tracing: Update print fmt check to handle new __get_sockaddr() macro") is now in v5.18, so this wonky fix can be replaced with __sockaddr() and friends properly during the v5.19 merge window.

Affected products

Linux kernel: from 4.17 before 5.10.112; from 5.11 before 5.15.35; from 5.16 before 5.17.4; 5.18-rc1, 5.18-rc2 — fixed in 5.10.112, 5.15.35, 5.17.4

How to fix

Upgrade to a fixed version: Linux kernel 5.10.112, 5.15.35, 5.17.4. Check the vendor advisory for mitigations.

References

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