{"cve":"CVE-2021-47280","nvd":{"published":"2024-05-21T15:15:16.277","modified":"2026-06-17T04:17:05.557","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm: Fix use-after-free read in drm_getunique()\n\nThere is a time-of-check-to-time-of-use error in drm_getunique() due\nto retrieving file_priv->master prior to locking the device's master\nmutex.\n\nAn example can be seen in the crash report of the use-after-free error\nfound by Syzbot:\nhttps://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803\n\nIn the report, the master pointer was used after being freed. This is\nbecause another process had acquired the device's master mutex in\ndrm_setmaster_ioctl(), then overwrote fpriv->master in\ndrm_new_set_master(). The old value of fpriv->master was subsequently\nfreed before the mutex was unlocked.\n\nTo fix this, we lock the device's master mutex before retrieving the\npointer from from fpriv->master. This patch passes the Syzbot\nreproducer test.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.0},"cwes":["CWE-367","CWE-416"],"references":["https://git.kernel.org/stable/c/17dab9326ff263c62dab1dbac4492e2938a049e4","https://git.kernel.org/stable/c/491d52e0078860b33b6c14f0a7ac74ca1b603bd6","https://git.kernel.org/stable/c/7d233ba700ceb593905ea82b42dadb4ec8ef85e9","https://git.kernel.org/stable/c/b246b4c70c1250e7814f409b243000f9c0bf79a3","https://git.kernel.org/stable/c/b436acd1cf7fac0ba987abd22955d98025c80c2b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47280","score":0.00183,"percentile":0.07889,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}