CVE-2026-31435 netfs: Fix read abandonment during retry
A null pointer dereference in the Linux kernel netfs subsystem can cause a system crash during read request retries.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-31435?
CVE-2026-31435 is a high-severity vulnerability in Linux kernel, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix read abandonment during retry
Under certain circumstances, all the remaining subrequests from a read request will get abandoned during retry. The abandonment process expects the 'subreq' variable to be set to the place to start abandonment from, but it doesn't always have a useful value (it will be uninitialised on the first pass through the loop and it may point to a deleted subrequest on later passes).
Fix the first jump to "abandon:" to set subreq to the start of the first subrequest expected to need retry (which, in this abandonment case, turned out unexpectedly to no longer have NEED_RETRY set).
Also clear the subreq pointer after discarding superfluous retryable subrequests to cause an oops if we do try to access it.
Which versions are affected by CVE-2026-31435?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31435?
Apply the vendor's patch.
Is CVE-2026-31435 being exploited?
There is no known exploitation of CVE-2026-31435 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31435, DEBIAN-CVE-2026-31435, GHSA-qfvq-ggc7-jqgw, ROOT-OS-DEBIAN-13-CVE-2026-31435, UBUNTU-CVE-2026-31435.