CVE-2026-31642 rxrpc: Fix call removal to use RCU safe deletion
A flaw in the Linux kernel's rxrpc module can cause an infinite loop when reading /proc/net/rxrpc/calls, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31642?
CVE-2026-31642 is a medium-severity denial of service vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-835
Which versions are affected by CVE-2026-31642?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31642?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-31642 being exploited?
There is no known exploitation of CVE-2026-31642 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-83756, BELL-CVE-2026-31642, DEBIAN-CVE-2026-31642, GHSA-q4rh-73g2-jf4j, ROOT-OS-DEBIAN-11-CVE-2026-31642, ROOT-OS-DEBIAN-12-CVE-2026-31642 and 4 more.