CVE-2024-49881

MEDIUM EPSS 16.1%
Published Oct 21, 20241y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Oct 21, 2024 1y ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: update orig_path in ext4_find_extent() In ext4_find_extent(), if the path is not big enough, we free it and set *orig_path to NULL. But after reallocating and successfully initializing the path, we don't update *orig_path, in which case the caller gets a valid path but a NULL ppath, and this may cause a NULL pointer dereference or a path memory leak. For example: ext4_split_extent path = *ppath = 2000 ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path = 2000); *orig_path = path = NULL; path = kcalloc() = 3000 ext4_split_extent_at(*ppath = NULL) path = *ppath; ex = path[depth].p_ext; // NULL pointer dereference! ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000010 CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847 RIP: 0010:ext4_split_extent_at+0x6d/0x560 Call Trace: <TASK> ext4_split_extent.isra.0+0xcb/0x1b0 ext4_ext_convert_to_initialized+0x168/0x6c0 ext4_ext_handle_unwritten_extents+0x325/0x4d0 ext4_ext_map_blocks+0x520/0xdb0 ext4_map_blocks+0x2b0/0x690 ext4_iomap_begin+0x20e/0x2c0 [...] ================================================================== Therefore, *orig_path is updated when the extent lookup succeeds, so that the caller can safely use path or *ppath.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
16.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel*≥3.18  –  <5.10.227
linuxlinux_kernel*≥5.11  –  <5.15.168
linuxlinux_kernel*≥5.16  –  <6.1.113
linuxlinux_kernel*≥6.2  –  <6.6.55
linuxlinux_kernel*≥6.7  –  <6.10.14
linuxlinux_kernel*≥6.11  –  <6.11.3

References 10

  • git.kernel.org https://git.kernel.org/stable/c/11b230100d6801c014fab2afabc8bdea304c1b96
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5b4b2dcace35f618fe361a87bae6f0d13af31bc1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6766937d0327000ac1b87c97bbecdd28b0dd6599
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6801ed1298204d16a38571091e31178bfdc3c679
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a9fcb1717d75061d3653ed69365c8d45331815cd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b63481b3a388ee2df9e295f97273226140422a42
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ec0c0beb9b777cdd1edd7df9b36e0f3e67e2bdff
  • git.kernel.org https://git.kernel.org/stable/c/f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/11b230100d6801c014fab2afabc8bdea304c1b96
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5b4b2dcace35f618fe361a87bae6f0d13af31bc1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6766937d0327000ac1b87c97bbecdd28b0dd6599
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6801ed1298204d16a38571091e31178bfdc3c679
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a9fcb1717d75061d3653ed69365c8d45331815cd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b63481b3a388ee2df9e295f97273226140422a42
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2
    Patch