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

memcg: fix possible use-after-free in memcg_write_event_control()

memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.

Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.

Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 23 Dec 2024 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Fri, 01 Nov 2024 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.1:rc8:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Tue, 22 Oct 2024 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 22 Oct 2024 13:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Mon, 21 Oct 2024 20:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: memcg: fix possible use-after-free in memcg_write_event_control() memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to 347c4a874710 ("memcg: remove cgroup_event->cft"), there was a call to __file_cft() which verified that the specified file is a regular cgroupfs file before further accesses. The cftype pointer returned from __file_cft() was no longer necessary and the commit inadvertently dropped the file type check with it allowing any file to slip through. With the invarients broken, the d_name and parent accesses can now race against renames and removals of arbitrary files and cause use-after-free's. Fix the bug by resurrecting the file type check in __file_cft(). Now that cgroupfs is implemented through kernfs, checking the file operations needs to go through a layer of indirection. Instead, let's check the superblock and dentry type.
Title memcg: fix possible use-after-free in memcg_write_event_control()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T08:27:35.599Z

Reserved: 2024-08-22T01:27:53.634Z

Link: CVE-2022-48988

cve-icon Vulnrichment

Updated: 2024-10-22T13:17:00.743Z

cve-icon NVD

Status : Analyzed

Published: 2024-10-21T20:15:10.710

Modified: 2024-11-01T15:20:42.073

Link: CVE-2022-48988

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-10-21T00:00:00Z

Links: CVE-2022-48988 - Bugzilla

cve-icon OpenCVE Enrichment

No data.