{"id":"CVE-2026-43278","summary":"dm: clear cloned request bio pointer when last clone bio completes","details":"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-\u003ebio 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-\u003ebio 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-\u003eend_io()                  // end_clone_request()\n          dm_complete_request(tio-\u003eorig)\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.","modified":"2026-06-18T03:55:54.549856447Z","published":"2026-05-06T11:29:00.193Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43278.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7daf279c674d515fb22a727a7bbc92aeb35c5442"},{"type":"WEB","url":"https://git.kernel.org/stable/c/83d72091804600ead96dc9e9f518ea56cb4942f6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8d9ddad561136f7e6a9346767bf97b4d79e38e67"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b1c1a2637ebd675aa2d71fee8c70da8791d73850"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e2e738e8dfbbf83bd2bae0467ec4420cc52da42a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fb8a6c18fb9a6561f7a15b58b272442b77a242dd"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43278.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43278"},{"type":"FIX","url":"https://git.kernel.org/stable/c/3d746b639be4b4f5cd8ce2b06aa52dc443f50edc"},{"type":"FIX","url":"https://git.kernel.org/stable/c/9a95b98202113045bc1a5bcb30388a500f25e050"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ab3e1d3bbab9e973aeb4dd4603251578658a47ff"},{"fixed":"8d9ddad561136f7e6a9346767bf97b4d79e38e67"},{"fixed":"7daf279c674d515fb22a727a7bbc92aeb35c5442"},{"fixed":"e2e738e8dfbbf83bd2bae0467ec4420cc52da42a"},{"fixed":"b1c1a2637ebd675aa2d71fee8c70da8791d73850"},{"fixed":"83d72091804600ead96dc9e9f518ea56cb4942f6"},{"fixed":"fb8a6c18fb9a6561f7a15b58b272442b77a242dd"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43278.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.1.0"},{"fixed":"6.1.165"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.16"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43278.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}