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cveLinuxCVE-2024-46701
HistorySep 13, 2024 - 7:15 a.m.

CVE-2024-46701

2024-09-1307:15:05
CWE-835
Linux
web.nvd.nist.gov
25
linux kernel
libfs
vulnerability fix
infinite directory reads

CVSS3

5.5

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

AI Score

6.5

Confidence

High

EPSS

0

Percentile

9.6%

In the Linux kernel, the following vulnerability has been resolved:

libfs: fix infinite directory reads for offset dir

After we switch tmpfs dir operations from simple_dir_operations to
simple_offset_dir_operations, every rename happened will fill new dentry
to dest dir’s maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free
key starting with octx->newx_offset, and then set newx_offset equals to
free key + 1. This will lead to infinite readdir combine with rename
happened at the same time, which fail generic/736 in xfstests(detail show
as below).

  1. create 5000 files(1 2 3…) under one dir
  2. call readdir(man 3 readdir) once, and get one entry
  3. rename(entry, “TEMPFILE”), then rename(“TEMPFILE”, entry)
  4. loop 2~3, until readdir return nothing or we loop too many
    times(tmpfs break test with the second condition)

We choose the same logic what commit 9b378f6ad48cf (“btrfs: fix infinite
directory reads”) to fix it, record the last_index when we open dir, and
do not emit the entry which index >= last_index. The file->private_data
now used in offset dir can use directly to do this, and we also update
the last_index when we llseek the dir file.

[brauner: only update last_index after seek when offset is zero like Jan suggested]

Affected configurations

Nvd
Vulners
Node
linuxlinux_kernelRange6.66.10.7
OR
linuxlinux_kernelMatch6.11rc1
OR
linuxlinux_kernelMatch6.11rc2
OR
linuxlinux_kernelMatch6.11rc3
VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linuxlinux_kernel6.11cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*
linuxlinux_kernel6.11cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*
linuxlinux_kernel6.11cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/libfs.c"
    ],
    "versions": [
      {
        "version": "a2e459555c5f",
        "lessThan": "308b4fc2403b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "a2e459555c5f",
        "lessThan": "64a7ce76fb90",
        "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/libfs.c"
    ],
    "versions": [
      {
        "version": "6.6",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.6",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.7",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]

CVSS3

5.5

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

AI Score

6.5

Confidence

High

EPSS

0

Percentile

9.6%

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