CVE-2024-56549

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1	Patch
https://git.kernel.org/stable/c/785408bbafcfa24c9fc5b251f03fd0780ce182bd
https://git.kernel.org/stable/c/9582c7664103c9043e80a78f5c382aa6bdd67418	Patch
https://git.kernel.org/stable/c/d6bba3ece960129a553d4b16f1b00c884dc0993a
https://git.kernel.org/stable/c/f98770440c9bc468e2fd878212ec9526dbe08293	Patch
https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

History

No history.

Information

Published : 2024-12-27 14:15

Updated : 2025-11-03 20:16

NVD link : CVE-2024-56549

Mitre link : CVE-2024-56549

CVE.ORG link : CVE-2024-56549

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-476

NULL Pointer Dereference

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