CVE-2021-47004

2024-02-2809:15:38

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

2072

cve-2021-47004

linux kernel

f2fs

vulnerability

fix

checkpointed data

lfs

ssr

at_ssr

data corruption

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

JSON

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:

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.

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 configurations

Vulners

Node

linuxlinux_kernelRange4.20–5.10.38

linuxlinux_kernelRange5.11.0–5.11.22

linuxlinux_kernelRange5.12.0–5.12.5

linuxlinux_kernelRange5.13.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/f2fs/f2fs.h",
      "fs/f2fs/gc.c",
      "fs/f2fs/segment.c",
      "fs/f2fs/segment.h"
    ],
    "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",
    "programFiles": [
      "fs/f2fs/f2fs.h",
      "fs/f2fs/gc.c",
      "fs/f2fs/segment.c",
      "fs/f2fs/segment.h"
    ],
    "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"
      }
    ]
  }
]