CVEvulnerability
CVE-2024-56549
5.5 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2024-12-27
- Last modified
- 2026-10-15
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-476
Description
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: Fix NULL pointer dereference in object->file
At present, the object->file has the NULL pointer dereference problem in
ondemand-mode. The root cause is that the allocated fd and object->file
lifetime are inconsistent, and the user-space invocation to anon_fd uses
object->file. Following is the process that triggers the issue:
[write fd] [umount]
cachefiles_ondemand_fd_write_iter
fscache_cookie_state_machine
cachefiles_withdraw_cookie
if (!file) return -ENOBUFS
cachefiles_clean_up_object
cachefiles_unmark_inode_in_use
fput(object->file)
object->file = NULL
// file NULL pointer dereference!
__cachefiles_write(..., file, ...)
Fix this issue by add an additional reference count to the object->file
before write/llseek, and decrement after it finished.
Affected configurations
• linux linux kernel (>= 5.19 < 6.11.11)
• linux linux kernel (>= 6.12 < 6.12.2)
Related
Weakness · CWE (1)
- CWE-476 NULL Pointer Dereference weakness
References
- https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1 Patch
- https://git.kernel.org/stable/c/785408bbafcfa24c9fc5b251f03fd0780ce182bd git.kernel.org
- https://git.kernel.org/stable/c/9582c7664103c9043e80a78f5c382aa6bdd67418 Patch
- https://git.kernel.org/stable/c/d6bba3ece960129a553d4b16f1b00c884dc0993a git.kernel.org
- https://git.kernel.org/stable/c/f98770440c9bc468e2fd878212ec9526dbe08293 Patch
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html lists.debian.org