{"id":"CVE-2026-43484","title":"mmc: core: Avoid bitfield RMW for claim/retune flags","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmmc: core: Avoid bitfield RMW for claim/retune flags\n\nMove claimed and retune control flags out of the bitfield word to\navoid unrelated RMW side effects in asynchronous…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 41dce4dae583a8ce06a7ebf4ce704c46a142957c","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < bb7fc2498c3bb25fa6a91f22f4760005325cfbd5","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 270277c2ab631044867adb1bd2f2433d3892de6e","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 45038e03f15e992c48603fff8c6b1c9be5397ac9","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 0e06cc511c61cff1591e5435a207759adcc76b6d","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc","Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 901084c51a0a8fb42a3f37d2e9c62083c495f824","Linux 4.15"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T15:40:59.499561Z"},"published":"2026-05-13","updated":"2026-11-06","sourceUpdated":"2026-11-06T15:42:57.242Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43484","references":[{"url":"https://git.kernel.org/stable/c/41dce4dae583a8ce06a7ebf4ce704c46a142957c"},{"url":"https://git.kernel.org/stable/c/bb7fc2498c3bb25fa6a91f22f4760005325cfbd5"},{"url":"https://git.kernel.org/stable/c/270277c2ab631044867adb1bd2f2433d3892de6e"},{"url":"https://git.kernel.org/stable/c/45038e03f15e992c48603fff8c6b1c9be5397ac9"},{"url":"https://git.kernel.org/stable/c/0e06cc511c61cff1591e5435a207759adcc76b6d"},{"url":"https://git.kernel.org/stable/c/d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc"},{"url":"https://git.kernel.org/stable/c/901084c51a0a8fb42a3f37d2e9c62083c495f824"}],"tags":["cve.org"],"epss":0.00114,"epssPercentile":0.01498,"ingestedAt":"2026-11-06T15:54:03.899Z","slug":"CVE-2026-43484","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmmc: core: Avoid bitfield RMW for claim/retune flags\n\nMove claimed and retune control flags out of the bitfield word to\navoid unrelated RMW side effects in asynchronous contexts.\n\nThe host->claimed bit shared a word with retune flags. Writes to claimed\nin __mmc_claim_host() or retune_now in mmc_mq_queue_rq() can overwrite\nother bits when concurrent updates happen in other contexts, triggering\nspurious WARN_ON(!host->claimed). Convert claimed, can_retune,\nretune_now and retune_paused to bool to remove shared-word coupling.\n\n## Affected\n\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 41dce4dae583a8ce06a7ebf4ce704c46a142957c`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < bb7fc2498c3bb25fa6a91f22f4760005325cfbd5`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 270277c2ab631044867adb1bd2f2433d3892de6e`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 45038e03f15e992c48603fff8c6b1c9be5397ac9`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 0e06cc511c61cff1591e5435a207759adcc76b6d`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc`\n- `Linux >= 6c0cedd1ef9527ef13e66875746570e76a3188a7 < 901084c51a0a8fb42a3f37d2e9c62083c495f824`\n- `Linux 4.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}