{"id":"CVE-2026-43278","title":"dm: clear cloned request bio pointer when last clone bio completes","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm: clear cloned request bio pointer when last clone bio completes\n\nStale rq->bio values have been observed to cause double-initialization of\ncloned bios in request-bas…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 8d9ddad561136f7e6a9346767bf97b4d79e38e67","Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 7daf279c674d515fb22a727a7bbc92aeb35c5442","Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < e2e738e8dfbbf83bd2bae0467ec4420cc52da42a","Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < b1c1a2637ebd675aa2d71fee8c70da8791d73850","Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 83d72091804600ead96dc9e9f518ea56cb4942f6","Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < fb8a6c18fb9a6561f7a15b58b272442b77a242dd","Linux 6.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:16:11.058094Z"},"published":"2026-05-06","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:38.038Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43278","references":[{"url":"https://git.kernel.org/stable/c/8d9ddad561136f7e6a9346767bf97b4d79e38e67"},{"url":"https://git.kernel.org/stable/c/7daf279c674d515fb22a727a7bbc92aeb35c5442"},{"url":"https://git.kernel.org/stable/c/e2e738e8dfbbf83bd2bae0467ec4420cc52da42a"},{"url":"https://git.kernel.org/stable/c/b1c1a2637ebd675aa2d71fee8c70da8791d73850"},{"url":"https://git.kernel.org/stable/c/83d72091804600ead96dc9e9f518ea56cb4942f6"},{"url":"https://git.kernel.org/stable/c/fb8a6c18fb9a6561f7a15b58b272442b77a242dd"}],"tags":["cve.org"],"epss":0.00171,"epssPercentile":0.06043,"ingestedAt":"2026-10-16T17:24:46.690Z","slug":"CVE-2026-43278","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndm: clear cloned request bio pointer when last clone bio completes\n\nStale rq->bio values have been observed to cause double-initialization of\ncloned bios in request-based device-mapper targets, leading to\nuse-after-free and double-free scenarios.\n\nOne such case occurs when using dm-multipath on top of a PCIe NVMe\nnamespace, where cloned request bios are freed during\nblk_complete_request(), but rq->bio is left intact. Subsequent clone\nteardown then attempts to free the same bios again via\nblk_rq_unprep_clone().\n\nThe resulting double-free path looks like:\n\n  nvme_pci_complete_batch()\n    nvme_complete_batch()\n      blk_mq_end_request_batch()\n        blk_complete_request()        // called on a DM clone request\n          bio_endio()                 // first free of all clone bios\n          ...\n        rq->end_io()                  // end_clone_request()\n          dm_complete_request(tio->orig)\n            dm_softirq_done()\n              dm_done()\n                dm_end_request()\n                  blk_rq_unprep_clone()  // second free of clone bios\n\nFix this by clearing the clone request's bio pointer when the last cloned\nbio completes, ensuring that later teardown paths do not attempt to free\nalready-released bios.\n\n## Affected\n\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 8d9ddad561136f7e6a9346767bf97b4d79e38e67`\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 7daf279c674d515fb22a727a7bbc92aeb35c5442`\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < e2e738e8dfbbf83bd2bae0467ec4420cc52da42a`\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < b1c1a2637ebd675aa2d71fee8c70da8791d73850`\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < 83d72091804600ead96dc9e9f518ea56cb4942f6`\n- `Linux >= ab3e1d3bbab9e973aeb4dd4603251578658a47ff < fb8a6c18fb9a6561f7a15b58b272442b77a242dd`\n- `Linux 6.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}