CVE-2024-49883

HIGH EPSS 19.3%
Published Oct 21, 20241y ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
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Published Oct 21, 2024 1y ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: aovid use-after-free in ext4_ext_insert_extent() As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and cause UAF. Below is a sample trace with dummy values: ext4_ext_insert_extent path = *ppath = 2000 ext4_ext_create_new_leaf(ppath) ext4_find_extent(ppath) path = *ppath = 2000 if (depth > path[0].p_maxdepth) kfree(path = 2000); *ppath = path = NULL; path = kcalloc() = 3000 *ppath = 3000; return path; /* here path is still 2000, UAF! */ eh = path[depth].p_hdr ================================================================== BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330 Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179 CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866 Call Trace: <TASK> ext4_ext_insert_extent+0x26d4/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 [...] Allocated by task 179: ext4_find_extent+0x81c/0x1f70 ext4_ext_map_blocks+0x146/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] Freed by task 179: kfree+0xcb/0x240 ext4_find_extent+0x7c0/0x1f70 ext4_ext_insert_extent+0xa26/0x3330 ext4_ext_map_blocks+0xe22/0x2d40 ext4_map_blocks+0x71e/0x1700 ext4_do_writepages+0x1290/0x2800 ext4_writepages+0x26d/0x4e0 do_writepages+0x175/0x700 [...] ================================================================== So use *ppath to update the path to avoid the above problem.

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
19.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 9

VendorProductVersionRange
debiandebian_linux11.0any
linuxlinux_kernel*≥3.18  –  <4.19.323
linuxlinux_kernel*≥4.20  –  <5.4.285
linuxlinux_kernel*≥5.5  –  <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 11

  • git.kernel.org https://git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5e811066c5ab709b070659197dccfb80ab650ddd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8162ee5d94b8c0351be0a9321be134872a7654a1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/975ca06f3fd154c5f7742083e7b2574c57d1c0c3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a164f3a432aae62ca23d03e6d926b122ee5b860d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/beb7b66fb489041c50c6473100b383f7a51648fc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
    Mailing ListThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
    Mailing ListThird Party Advisory

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/51db04892a993cace63415be99848970a0f15ef2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5e811066c5ab709b070659197dccfb80ab650ddd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8162ee5d94b8c0351be0a9321be134872a7654a1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/975ca06f3fd154c5f7742083e7b2574c57d1c0c3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9df59009dfc6d9fc1bd9ddf6c5ab6e56d6ed887a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a164f3a432aae62ca23d03e6d926b122ee5b860d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/beb7b66fb489041c50c6473100b383f7a51648fc
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/bfed082ce4b1ce6349b05c09a0fa4f3da35ecb1b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e17ebe4fdd7665c93ae9459ba40fcdfb76769ac1
    Patch