Bug 2477080 (CVE-2026-43484) - CVE-2026-43484 kernel: mmc: core: Avoid bitfield RMW for claim/retune flags
Summary: CVE-2026-43484 kernel: mmc: core: Avoid bitfield RMW for claim/retune flags
Keywords:
Status: NEW
Alias: CVE-2026-43484
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-13 16:03 UTC by OSIDB Bzimport
Modified: 2026-05-13 17:18 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-05-13 16:03:01 UTC
In the Linux kernel, the following vulnerability has been resolved:

mmc: core: Avoid bitfield RMW for claim/retune flags

Move claimed and retune control flags out of the bitfield word to
avoid unrelated RMW side effects in asynchronous contexts.

The host->claimed bit shared a word with retune flags. Writes to claimed
in __mmc_claim_host() or retune_now in mmc_mq_queue_rq() can overwrite
other bits when concurrent updates happen in other contexts, triggering
spurious WARN_ON(!host->claimed). Convert claimed, can_retune,
retune_now and retune_paused to bool to remove shared-word coupling.


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