Vulnerability Details : CVE-2021-47004
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid touching checkpointed data in get_victim()
In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR
mode to select victim:
1. LFS is set to find source section during GC, the victim should have
no checkpointed data, since after GC, section could not be set free for
reuse.
Previously, we only check valid chpt blocks in current segment rather
than section, fix it.
2. SSR | AT_SSR are set to find target segment for writes which can be
fully filled by checkpointed and newly written blocks, we should never
select such segment, otherwise it can cause panic or data corruption
during allocation, potential case is described as below:
a) target segment has 'n' (n < 512) ckpt valid blocks
b) GC migrates 'n' valid blocks to other segment (segment is still
in dirty list)
c) GC migrates '512 - n' blocks to target segment (segment has 'n'
cp_vblocks and '512 - n' vblocks)
d) If GC selects target segment via {AT,}SSR allocator, however there
is no free space in targe segment.
Products affected by CVE-2021-47004
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47004
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 5 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47004
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
7.1
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H |
1.8
|
5.2
|
NIST | 2025-01-08 |
References for CVE-2021-47004
-
https://git.kernel.org/stable/c/61461fc921b756ae16e64243f72af2bfc2e620db
f2fs: fix to avoid touching checkpointed data in get_victim() - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/211372b2571520e394b56b431a0705586013b3ff
f2fs: fix to avoid touching checkpointed data in get_victim() - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/1e116f87825f01a6380286472196882746b16f63
f2fs: fix to avoid touching checkpointed data in get_victim() - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/105155a8146ddb54c119d8318964eef3859d109d
f2fs: fix to avoid touching checkpointed data in get_victim() - kernel/git/stable/linux.git - Linux kernel stable treePatch
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