CVE-2026-31642: rxrpc: Fix call removal to use RCU safe deletion

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-24 · updated 2026-10-15
Weakness: CWE-835

Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix call removal to use RCU safe deletion Fix rxrpc call removal from the rxnet->calls list to use list_del_rcu() rather than list_del_init() to prevent stuffing up reading /proc/net/rxrpc/calls from potentially getting into an infinite loop. This, however, means that list_empty() no longer works on an entry that's been deleted from the list, making it harder to detect prior deletion. Fix this by: Firstly, make rxrpc_destroy_all_calls() only dump the first ten calls that are unexpectedly still on the list. Limiting the number of steps means there's no need to call cond_resched() or to remove calls from the list here, thereby eliminating the need for rxrpc_put_call() to check for that. rxrpc_put_call() can then be fixed to unconditionally delete the call from the list as it is the only place that the deletion occurs.

Affected products

Linux kernel: from 4.13.1 before 6.6.135; from 6.7 before 6.12.82; from 6.13 before 6.18.23; from 6.19 before 6.19.13; 4.13, 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5 (+2) — fixed in 6.12.82, 6.18.23, 6.19.13, 6.6.135

How to fix

Upgrade to a fixed version: Linux kernel 6.12.82, 6.18.23, 6.19.13, 6.6.135. Check the vendor advisory for mitigations.

References

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