CVE-2026-43278
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-415
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/7daf279c674d515fb22a727a7bbc92aeb35c5442Patch
- https://git.kernel.org/stable/c/83d72091804600ead96dc9e9f518ea56cb4942f6Patch
- https://git.kernel.org/stable/c/8d9ddad561136f7e6a9346767bf97b4d79e38e67Patch
- https://git.kernel.org/stable/c/b1c1a2637ebd675aa2d71fee8c70da8791d73850Patch
- https://git.kernel.org/stable/c/e2e738e8dfbbf83bd2bae0467ec4420cc52da42aPatch
- https://git.kernel.org/stable/c/fb8a6c18fb9a6561f7a15b58b272442b77a242ddPatch
- https://git.kernel.org/stable/c/3d746b639be4b4f5cd8ce2b06aa52dc443f50edcPatch
- https://git.kernel.org/stable/c/9a95b98202113045bc1a5bcb30388a500f25e050Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.