CVE-2026-68179
misc: nsm: only unlock nsm_dev on post-lock error paths
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: misc: nsm: only unlock nsm_dev on post-lock error paths nsm_dev_ioctl() jumps to the common out label even when the initial copy_from_user() fails before nsm->lock has been taken. The error path then blindly unlocks a mutex that was never acquired. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the miscdevice ioctl entry and the pre-lock copy_from_user(&raw, argp, _IOC_SIZE(cmd)) failure path by issuing NSM_IOCTL_RAW with an invalid user pointer. That failure reaches the shared out label before mutex_lock(&nsm->lock). Lockdep reported: WARNING: bad unlock balance detected! exploit/193 is trying to release lock (&global_nsm.lock) at: nsm_dev_ioctl+0x5f/0xcf [vuln_msv] but there are no more locks to release! no locks held by exploit/193. Return immediately on the pre-lock copy_from_user() failure and keep the common unlock label for the post-lock paths only.
Timeline
ID reserved
By Linux
- 11 days later
· 11 days later
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High8.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.4.
Weakness
Affected products
- affected b9873755a6c8ccfce79094c4dce9efa3ecb1a749 – < 4aa3f7d48e91eb74a363c1b4d7dbdd28f5b341fb
- affected b9873755a6c8ccfce79094c4dce9efa3ecb1a749 – < 8f068342096b027181b168d91fef7ac7a2c64b25
- affected b9873755a6c8ccfce79094c4dce9efa3ecb1a749 – < f318f5a872cb9096536e759b23ae5c9873bb80ed
- affected b9873755a6c8ccfce79094c4dce9efa3ecb1a749 – < ce1fed11d18e163baf7f875152a33bf80f625c1a
- affected 6.8
- unaffected < 6.8
- unaffected 6.12.101 – ≤ 6.12.*
- unaffected 6.18.42 – ≤ 6.18.*
- unaffected 7.1.6 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References (4)
- https://git.kernel.org/stable/c/4aa3f7d48e91eb74a363c1b4d7dbdd28f5b341fb (opens in a new tab)
- https://git.kernel.org/stable/c/8f068342096b027181b168d91fef7ac7a2c64b25 (opens in a new tab)
- https://git.kernel.org/stable/c/f318f5a872cb9096536e759b23ae5c9873bb80ed (opens in a new tab)
- https://git.kernel.org/stable/c/ce1fed11d18e163baf7f875152a33bf80f625c1a (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-68179)Record last updated .