CVE-2022-49065

/// Technical 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 b

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References