Bug 2402187 (CVE-2023-53622)

Summary: CVE-2023-53622 kernel: gfs2: Fix possible data races in gfs2_show_options()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A race condition was found in the Linux kernel's GFS2 filesystem in the mount options display logic. A local user can trigger this issue by concurrently reading filesystem mount options while another process modifies filesystem tuning parameters, causing gfs2_show_options to read fields like gt_logd_secs without holding the gt_spin lock. This results in data races that can produce inconsistent or corrupted output, potentially leading to denial of service through system instability.
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Description OSIDB Bzimport 2025-10-07 16:01:34 UTC
In the Linux kernel, the following vulnerability has been resolved:

gfs2: Fix possible data races in gfs2_show_options()

Some fields such as gt_logd_secs of the struct gfs2_tune are accessed
without holding the lock gt_spin in gfs2_show_options():

  val = sdp->sd_tune.gt_logd_secs;
  if (val != 30)
    seq_printf(s, ",commit=%d", val);

And thus can cause data races when gfs2_show_options() and other functions
such as gfs2_reconfigure() are concurrently executed:

  spin_lock(&gt->gt_spin);
  gt->gt_logd_secs = newargs->ar_commit;

To fix these possible data races, the lock sdp->sd_tune.gt_spin is
acquired before accessing the fields of gfs2_tune and released after these
accesses.

Further changes by Andreas:

- Don't hold the spin lock over the seq_printf operations.