CVE-2021-47004
Assigner: Linux
Published: 2024-02-28T08:13:25.324Z
State: PUBLISHED
descriptions: value: 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.
affected: product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 4354994f097d
lessThan: 105155a8146d
status: affected
versionType: git
version: 4354994f097d
lessThan: 1e116f87825f
status: affected
versionType: git
version: 4354994f097d
lessThan: 211372b25715
status: affected
versionType: git
version: 4354994f097d
lessThan: 61461fc921b7
status: affected
versionType: git
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions: version: 4.20
status: affected
version: 0
lessThan: 4.20
status: unaffected
versionType: custom
version: 5.10.38
lessThanOrEqual: 5.10.*
status: unaffected
versionType: custom
version: 5.11.22
lessThanOrEqual: 5.11.*
status: unaffected
versionType: custom
version: 5.12.5
lessThanOrEqual: 5.12.*
status: unaffected
versionType: custom
version: 5.13
lessThanOrEqual: *
status: unaffected
versionType: original_commit_for_fix
title: f2fs: fix to avoid touching checkpointed data in get_victim()
x_generator: engine: bippy-5f0117140d9a