CVE-2021-47280
drm: Fix use-after-free read in drm_getunique()
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: drm: Fix use-after-free read in drm_getunique() There is a time-of-check-to-time-of-use error in drm_getunique() due to retrieving file_priv->master prior to locking the device's master mutex. An example can be seen in the crash report of the use-after-free error found by Syzbot: https://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803 In the report, the master pointer was used after being freed. This is because another process had acquired the device's master mutex in drm_setmaster_ioctl(), then overwrote fpriv->master in drm_new_set_master(). The old value of fpriv->master was subsequently freed before the mutex was unlocked. To fix this, we lock the device's master mutex before retrieving the pointer from from fpriv->master. This patch passes the Syzbot reproducer test.
Timeline
ID reserved
By Linux
Published
- 24 months later
· 24 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 |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.0 | CVSS:3.1/AV:L/AC:H/PR:L/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: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.0.
Weakness
Affected products
- affected 5acc614ac47465fee6375a9af4740f618830762d – < 17dab9326ff263c62dab1dbac4492e2938a049e4
- affected 5acc614ac47465fee6375a9af4740f618830762d – < 7d233ba700ceb593905ea82b42dadb4ec8ef85e9
- affected 5acc614ac47465fee6375a9af4740f618830762d – < b246b4c70c1250e7814f409b243000f9c0bf79a3
- affected 5acc614ac47465fee6375a9af4740f618830762d – < 491d52e0078860b33b6c14f0a7ac74ca1b603bd6
- affected 5acc614ac47465fee6375a9af4740f618830762d – < f773f8cccac13c7e7bbd9182e7996c727742488e
- affected 5acc614ac47465fee6375a9af4740f618830762d – < b436acd1cf7fac0ba987abd22955d98025c80c2b
- affected 4.11
- unaffected < 4.11
- unaffected 4.14.237 – ≤ 4.14.*
- unaffected 4.19.195 – ≤ 4.19.*
- unaffected 5.4.126 – ≤ 5.4.*
- unaffected 5.10.44 – ≤ 5.10.*
- unaffected 5.12.11 – ≤ 5.12.*
- unaffected 5.13 – ≤ *
References (6)
- https://git.kernel.org/stable/c/17dab9326ff263c62dab1dbac4492e2938a049e4 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/7d233ba700ceb593905ea82b42dadb4ec8ef85e9 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/b246b4c70c1250e7814f409b243000f9c0bf79a3 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/491d52e0078860b33b6c14f0a7ac74ca1b603bd6 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/f773f8cccac13c7e7bbd9182e7996c727742488e (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/b436acd1cf7fac0ba987abd22955d98025c80c2b (opens in a new tab)x_transferred
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-2021-47280)Record last updated .