CVE-2021-47200
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2021-47200
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47200.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2021-47200
- Downstream
- Related
- Published
- 2024-04-10T19:15:48Z
- Modified
- 2025-08-09T20:01:26Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
drm/prime: Fix use after free in mmap with drmgemttm_mmap
drmgemttmmmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drmgemprimemmap(), that drop will free the gem object, and the subsequent drmgemobject_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper.
This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drmgemobjectget() call in drmgemttmmmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero."
- References