CVEvulnerability
CVE-2026-93049
- Status
- Received
- Published
- 2026-09-17
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
mtd: mtdswap: Avoid freeing registered blktrans device twice
In mtdswap_add_mtd(), debugfs setup failure after successful blktrans
registration can free mbd_dev twice.
add_mtd_blktrans_dev() initializes the blktrans device reference and
publishes the disk. Once that succeeds, del_mtd_blktrans_dev() tears the
disk down and drops the blktrans reference; when that reference reaches
zero, blktrans_dev_release() frees the mtd_blktrans_dev.
The debugfs failure path called del_mtd_blktrans_dev(mbd_dev), then fell
through the common cleanup label and called kfree(mbd_dev) again. Clear
the local pointer after deregistration so the common cleanup can still
release the mtdswap state without freeing the blktrans object twice.
This issue was found by a static analysis checker and confirmed by
manual source review.
References
- https://git.kernel.org/stable/c/0ce48c6ddea1a8e675a2eb0221b62a9950788f3c git.kernel.org
- https://git.kernel.org/stable/c/37be7bc2c2d09c18e939da20224405864a0090b9 git.kernel.org
- https://git.kernel.org/stable/c/5c349c533e72af2313c3be0f80a24d7407fa4777 git.kernel.org
- https://git.kernel.org/stable/c/779aa4c66a96bf43d2d62982ea1a9096a9128d87 git.kernel.org
- https://git.kernel.org/stable/c/a82d93fcfdfd26af17049c34319dfdd079cd1901 git.kernel.org
- https://git.kernel.org/stable/c/d5086911d532b82ca070d944aa08ddde00baefe4 git.kernel.org
- https://git.kernel.org/stable/c/ecadb9137aeaa0615183f8d23eabea2b45c862f1 git.kernel.org
- https://git.kernel.org/stable/c/eec130fc9ffbbd08a5d5432683122b79aca2a726 git.kernel.org