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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2021-47281 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and snd_seq_timer_open() should have managed the concurrent accesses. It looks as if it's checking the already existing timer instance at the beginning, but it's not right, because there is no protection, hence any later concurrent call of snd_seq_timer_open() may override the timer instance easily. This may result in UAF, as the leftover timer instance can keep running while the queue itself gets closed, as spotted by syzkaller recently. For avoiding the race, add a proper check at the assignment of tmr->timeri again, and return -EBUSY if it's been already registered.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031 Patch 
https://git.kernel.org/stable/c/536a7646c00a0f14fee49e5e313109e5da2f6031 Patch 
https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273 Patch 
https://git.kernel.org/stable/c/83e197a8414c0ba545e7e3916ce05f836f349273 Patch 
https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba Patch 
https://git.kernel.org/stable/c/bd7d88b0874f82f7b29d1a53e574cedaf23166ba Patch 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-416 Use After Free cwe source acceptance level NIST  

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-47281
NVD Published Date:
05/21/2024
NVD Last Modified:
12/24/2024
Source:
kernel.org