Bug 2562705 (CVE-2026-99136)

Summary: CVE-2026-99136 kernel: kernel: Data corruption via race condition in dm-crypt
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's dm-crypt subsystem. A race condition occurs during pending disk encryption request processing where the error status is read before reference counting is completed. During concurrent input/output (I/O) operations, this flaw causes failed read or write operations to be incorrectly reported as successful. Consequently, this issue can lead to silent data corruption or applications processing stale, unencrypted data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-28 10:53:17 UTC
In the Linux kernel, the following vulnerability has been resolved:

dm-crypt: fix a tiny race condition in crypt_dec_pending

crypt_dec_pending reads io->error before calling atomic_dec_and_test.
Another context, for example crypt_endio called from an interrupt, may
set io->error and drop its reference between the read and the
decrement. crypt_dec_pending then drops the last reference and completes
the bio with the stale status - so a read that failed and was never
decrypted, or a write that failed, is reported as successful.

The read was placed before the decrement by commit b35f8caa0890 ("dm
crypt: wait for endio to complete before destruction"), because that
commit freed dm_crypt_io before calling bio_endio. This is no longer the
case, dm_crypt_io lives in the per-bio data now.

Read io->error after atomic_dec_and_test instead. atomic_dec_and_test is
fully ordered, so no additional barrier is needed.