CVE-2026-93049
mtd: mtdswap: Avoid freeing registered blktrans device twice
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.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 17, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the patched version.
- Rebuild and deploy the modified kernel.
- Reboot systems with the updated kernel.
References to Advisories, Solutions, and Tools
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CVE-2026-93049.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93049 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-93049
weaknesses.
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93049.json">CVE-2026-93049</a> Added Reference https://git.kernel.org/stable/c/0ce48c6ddea1a8e675a2eb0221b62a9950788f3c Added Reference https://git.kernel.org/stable/c/37be7bc2c2d09c18e939da20224405864a0090b9 Added Reference https://git.kernel.org/stable/c/5c349c533e72af2313c3be0f80a24d7407fa4777 Added Reference https://git.kernel.org/stable/c/779aa4c66a96bf43d2d62982ea1a9096a9128d87 Added Reference https://git.kernel.org/stable/c/a82d93fcfdfd26af17049c34319dfdd079cd1901 Added Reference https://git.kernel.org/stable/c/d5086911d532b82ca070d944aa08ddde00baefe4 Added Reference https://git.kernel.org/stable/c/ecadb9137aeaa0615183f8d23eabea2b45c862f1 Added Reference https://git.kernel.org/stable/c/eec130fc9ffbbd08a5d5432683122b79aca2a726