Bug 2492457 (CVE-2026-53048)

Summary: CVE-2026-53048 kernel: gfs2: prevent NULL pointer dereference during unmount
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's gfs2 filesystem. During the unmount process, a NULL pointer dereference can occur when flushing outstanding glock work. This happens because `gfs2_log_flush()` is called when a critical data structure (`sdp->sd_jdesc`) has already been deallocated, and a subsequent dereference in `gfs2_log_release()` lacks a necessary NULL check. An attacker could potentially exploit this to cause a system crash, leading to a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-06-24 18:13:07 UTC
In the Linux kernel, the following vulnerability has been resolved:

gfs2: prevent NULL pointer dereference during unmount

When flushing out outstanding glock work during an unmount, gfs2_log_flush()
can be called when sdp->sd_jdesc has already been deallocated and sdp->sd_jdesc
is NULL.  Commit 35264909e9d1 ("gfs2: Fix NULL pointer dereference in
gfs2_log_flush") added a check for that to gfs2_log_flush() itself, but it
missed the sdp->sd_jdesc dereference in gfs2_log_release().  Fix that.

Comment 1 Mauro Matteo Cascella 2026-06-25 08:22:35 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062459-CVE-2026-53048-9cd0@gregkh/T