Bug 2492855 (CVE-2026-53272) - CVE-2026-53272 kernel: erofs: fix use-after-free on sbi->sync_decompress
Summary: CVE-2026-53272 kernel: erofs: fix use-after-free on sbi->sync_decompress
Keywords:
Status: NEW
Alias: CVE-2026-53272
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-25 10:09 UTC by OSIDB Bzimport
Modified: 2026-06-29 17:16 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-06-25 10:09:13 UTC
In the Linux kernel, the following vulnerability has been resolved:

erofs: fix use-after-free on sbi->sync_decompress

z_erofs_decompress_kickoff() can race with filesystem unmount, causing
a use-after-free on sbi->sync_decompress.

When I/O completes, z_erofs_endio() calls z_erofs_decompress_kickoff()
to queue z_erofs_decompressqueue_work() asynchronously. Then, after all
folios are unlocked, unmount workflow can proceed and sbi will be freed
before accessing to sbi->sync_decompress.

Thread (unmount)        I/O completion        kworker
                        queue_work
                                              z_erofs_decompressqueue_work
                                               (all folios are unlocked)
cleanup_mnt
 ..
 erofs_kill_sb
  erofs_sb_free
   kfree(sbi)
                        access sbi->sync_decompress  // UAF!!


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