CVE-2026-43278

Description

In the Linux kernel, the following vulnerability has been resolved: dm: clear cloned request bio pointer when last clone bio completes Stale rq->bio values have been observed to cause double-initialization of cloned bios in request-based device-mapper targets, leading to use-after-free and double-free scenarios. One such case occurs when using dm-multipath on top of a PCIe NVMe namespace, where cloned request bios are freed during blk_complete_request(), but rq->bio is left intact. Subsequent clone teardown then attempts to free the same bios again via blk_rq_unprep_clone(). The resulting double-free path looks like: nvme_pci_complete_batch() nvme_complete_batch() blk_mq_end_request_batch() blk_complete_request() // called on a DM clone request bio_endio() // first free of all clone bios ... rq->end_io() // end_clone_request() dm_complete_request(tio->orig) dm_softirq_done() dm_done() dm_end_request() blk_rq_unprep_clone() // second free of clone bios Fix this by clearing the clone request's bio pointer when the last cloned bio completes, ensuring that later teardown paths do not attempt to free already-released bios.

PUBLISHED Reserved 2026-05-01 | Published 2026-05-06 | Updated 2026-05-08 | Assigner Linux

Product status

References

git.kernel.org/...c/8d9ddad561136f7e6a9346767bf97b4d79e38e67

git.kernel.org/...c/7daf279c674d515fb22a727a7bbc92aeb35c5442

git.kernel.org/...c/e2e738e8dfbbf83bd2bae0467ec4420cc52da42a

git.kernel.org/...c/b1c1a2637ebd675aa2d71fee8c70da8791d73850

git.kernel.org/...c/83d72091804600ead96dc9e9f518ea56cb4942f6

git.kernel.org/...c/fb8a6c18fb9a6561f7a15b58b272442b77a242dd

cve.org (CVE-2026-43278)

nvd.nist.gov (CVE-2026-43278)

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