CVE-2026-43484

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

MEDIUM

5.5

CVSS Score

Published: May 13, 2026 at 03:08 PM UTC

Updated: June 27, 2026 at 11:41 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.1%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

4.15 ≤ v < 5.15.2034.15 ≤ v < 6.1.1674.15 ≤ v < 6.12.784.15 ≤ v < 6.18.194.15 ≤ v < 6.19.94.15 ≤ v < 6.6.1304.15 ≤ v < 7.05.16 ≤ v < 6.1.1676.13 ≤ v < 6.18.196.19 ≤ v < 6.19.96.2 ≤ v < 6.6.1306.7 ≤ v < 6.12.786c0cedd1ef9527ef13e66875746570e76a3188a77.0 rc1

Vendor states this is fixed in 0e06cc511c61cff1591e5435a207759adcc76b6d (fixed)

Vendor states this is fixed in 270277c2ab631044867adb1bd2f2433d3892de6e (fixed)

Vendor states this is fixed in 41dce4dae583a8ce06a7ebf4ce704c46a142957c (fixed)

Vendor states this is fixed in 45038e03f15e992c48603fff8c6b1c9be5397ac9 (fixed)

Vendor states this is fixed in 901084c51a0a8fb42a3f37d2e9c62083c495f824 (fixed)

Vendor states this is fixed in bb7fc2498c3bb25fa6a91f22f4760005325cfbd5 (fixed)

Vendor states this is fixed in d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc (fixed)

Vendor states this is fixed in 4.15 (unaffected)

Vendor states this is fixed in 5.15.203 (unaffected)

Vendor states this is fixed in 6.1.167 (unaffected)

Vendor states this is fixed in 6.12.78 (unaffected)

Vendor states this is fixed in 6.18.19 (unaffected)