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.
CVSS
No CVSS.
References
Configurations
No configuration.
History
21 Oct 2024, 20:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2024-10-21 20:15
Updated : 2024-10-21 20:15
NVD link : CVE-2022-48988
Mitre link : CVE-2022-48988
CVE.ORG link : CVE-2022-48988
JSON object : View
Products Affected
No product.
CWE
No CWE.