Vulnerability Details : CVE-2021-47342
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix possible UAF when remounting r/o a mmp-protected file system
After commit 618f003199c6 ("ext4: fix memory leak in
ext4_fill_super"), after the file system is remounted read-only, there
is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to
point at freed memory, which the call to ext4_stop_mmpd() can trip
over.
Fix this by only allowing kmmpd() to exit when it is stopped via
ext4_stop_mmpd().
Bug-Report-Link: <20210629143603.2166962-1-yebin10@huawei.com>
Products affected by CVE-2021-47342
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47342
0.03%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 6 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47342
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
NIST | 2024-12-26 |
CWE ids for CVE-2021-47342
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-47342
-
https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd
ext4: fix possible UAF when remounting r/o a mmp-protected file system - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6b
ext4: fix possible UAF when remounting r/o a mmp-protected file system - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cb
ext4: fix possible UAF when remounting r/o a mmp-protected file system - kernel/git/stable/linux.git - Linux kernel stable treePatch
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