Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 347c4a8747104a945ecced358944e42879176ca5 before b77600e26fd48727a95ffd50ba1e937efb548125; affected 347c4a8747104a945ecced358944e42879176ca5 before e1ae97624ecf400ea56c238bff23e5cd139df0b8; affected 347c4a8747104a945ecced358944e42879176ca5 before 35963b31821920908e397146502066f6b032c917; affected 347c4a8747104a945ecced358944e42879176ca5 before f1f7f36cf682fa59db15e2089039a2eeb58ff2ad; affected 347c4a8747104a945ecced358944e42879176ca5 before aad8bbd17a1d586005feb9226c2e9cfce1432e13; affected 347c4a8747104a945ecced358944e42879176ca5 before 0ed074317b835caa6c03bcfa8f133365324673dc; affected 347c4a8747104a945ecced358944e42879176ca5 before 4a7ba45b1a435e7097ca0f79a847d0949d0eb088 |
| Linux / Linux | affected 3.14; unaffected 0 before 3.14; unaffected 4.14.302 through 4.14.*; unaffected 4.19.269 through 4.19.*; unaffected 5.4.227 through 5.4.*; unaffected 5.10.159 through 5.10.*; unaffected 5.15.83 through 5.15.*; unaffected 6.0.13 through 6.0.*; unaffected 6.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/b77600e26fd48727a95ffd50ba1e937efb548125
- https://git.kernel.org/stable/c/e1ae97624ecf400ea56c238bff23e5cd139df0b8
- https://git.kernel.org/stable/c/35963b31821920908e397146502066f6b032c917
- https://git.kernel.org/stable/c/f1f7f36cf682fa59db15e2089039a2eeb58ff2ad
- https://git.kernel.org/stable/c/aad8bbd17a1d586005feb9226c2e9cfce1432e13
- https://git.kernel.org/stable/c/0ed074317b835caa6c03bcfa8f133365324673dc
- https://git.kernel.org/stable/c/4a7ba45b1a435e7097ca0f79a847d0949d0eb088
ADP enrichment
No English description supplied.
No references supplied.