Bug 2460660 (CVE-2026-31435)

Summary: CVE-2026-31435 kernel: netfs: Fix read abandonment during retry
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's netfs component. Under certain circumstances, during a read retry operation, the system may incorrectly abandon subrequests. This issue arises because a pointer (`subreq`) used in the abandonment process can be uninitialized or point to invalid memory. An attacker could potentially exploit this to trigger a kernel oops, leading to a system crash and a Denial of Service (DoS).
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-04-22 15:03:46 UTC 
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.
Comment 1 Keith Grant 2026-04-22 16:52:43 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042242-CVE-2026-31435-f0f5@gregkh/T