CVE - CVE-2021-47280

CVE-ID
CVE-2021-47280	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/17dab9326ff263c62dab1dbac4492e2938a049e4 URL:https://git.kernel.org/stable/c/17dab9326ff263c62dab1dbac4492e2938a049e4 MISC:https://git.kernel.org/stable/c/491d52e0078860b33b6c14f0a7ac74ca1b603bd6 URL:https://git.kernel.org/stable/c/491d52e0078860b33b6c14f0a7ac74ca1b603bd6 MISC:https://git.kernel.org/stable/c/7d233ba700ceb593905ea82b42dadb4ec8ef85e9 URL:https://git.kernel.org/stable/c/7d233ba700ceb593905ea82b42dadb4ec8ef85e9 MISC:https://git.kernel.org/stable/c/b246b4c70c1250e7814f409b243000f9c0bf79a3 URL:https://git.kernel.org/stable/c/b246b4c70c1250e7814f409b243000f9c0bf79a3 MISC:https://git.kernel.org/stable/c/b436acd1cf7fac0ba987abd22955d98025c80c2b URL:https://git.kernel.org/stable/c/b436acd1cf7fac0ba987abd22955d98025c80c2b MISC:https://git.kernel.org/stable/c/f773f8cccac13c7e7bbd9182e7996c727742488e URL:https://git.kernel.org/stable/c/f773f8cccac13c7e7bbd9182e7996c727742488e
Assigning CNA
kernel.org
Date Record Created
20240521	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240521)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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