CVE-2021-47004

published 2024-02-28

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…

Priority P4 27 high 7.1 CVSS 3.1

AV L AC L PR L UI N S U C N I H A H

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

13 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 5.10.38-1 (bookworm)	linux 5.10.38-1 (bookworm)
linux	linux	—	—
linux	linux	>= 4354994f097d068a894aa1a0860da54571df3582 < 105155a8146ddb54c119d8318964eef3859d109d	105155a8146ddb54c119d8318964eef3859d109d
linux	linux	>= 4354994f097d068a894aa1a0860da54571df3582 < 1e116f87825f01a6380286472196882746b16f63	1e116f87825f01a6380286472196882746b16f63
linux	linux	>= 4354994f097d068a894aa1a0860da54571df3582 < 211372b2571520e394b56b431a0705586013b3ff	211372b2571520e394b56b431a0705586013b3ff
linux	linux	>= 4354994f097d068a894aa1a0860da54571df3582 < 61461fc921b756ae16e64243f72af2bfc2e620db	61461fc921b756ae16e64243f72af2bfc2e620db
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 0 < 5.10.38-1	5.10.38-1
linux	linux_kernel	>= 4.20 < 5.10.38	5.10.38
linux	linux_kernel	>= 5.11 < 5.11.22	5.11.22
linux	linux_kernel	>= 5.12 < 5.12.5	5.12.5

CVSS provenance

nvd v3.1 7.1 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

osv 7.1 HIGH

vendor_debian 7.1 HIGH

vendor_redhat 7.1 HIGH

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