Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race on rawdata dereference There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 5d5182cae40115c03933989473288e54afb39c7c before 3b8e77c7abab40e6de9ad9de730d77984a498840; affected 5d5182cae40115c03933989473288e54afb39c7c before d9d8560b9b7932f8cffc4c068c14289220900f79; affected 5d5182cae40115c03933989473288e54afb39c7c before 6b6ba87579c7e7c669e0bec91823e7fb693bc5df; affected 5d5182cae40115c03933989473288e54afb39c7c before 6ef1f2926c41ab96952d9696d55a052f1b3a9418; affected 5d5182cae40115c03933989473288e54afb39c7c before f9761add6d100962a23996cb68f3d6abdd4d1815; affected 5d5182cae40115c03933989473288e54afb39c7c before af782cc8871e3683ddd5a3cd2f7df526599863a9; affected 5d5182cae40115c03933989473288e54afb39c7c before 763e838adc3c7ec5a7df2990ce84cad951e42721; affected 5d5182cae40115c03933989473288e54afb39c7c before a0b7091c4de45a7325c8780e6934a894f92ac86b |
| Linux / Linux | affected 4.13; unaffected 0 before 4.13; unaffected 5.10.253 through 5.10.*; unaffected 5.15.203 through 5.15.*; unaffected 6.1.169 through 6.1.*; unaffected 6.6.130 through 6.6.*; unaffected 6.12.77 through 6.12.*; unaffected 6.18.18 through 6.18.*; unaffected 6.19.8 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/3b8e77c7abab40e6de9ad9de730d77984a498840
- https://git.kernel.org/stable/c/d9d8560b9b7932f8cffc4c068c14289220900f79
- https://git.kernel.org/stable/c/6b6ba87579c7e7c669e0bec91823e7fb693bc5df
- https://git.kernel.org/stable/c/6ef1f2926c41ab96952d9696d55a052f1b3a9418
- https://git.kernel.org/stable/c/f9761add6d100962a23996cb68f3d6abdd4d1815
- https://git.kernel.org/stable/c/af782cc8871e3683ddd5a3cd2f7df526599863a9
- https://git.kernel.org/stable/c/763e838adc3c7ec5a7df2990ce84cad951e42721
- https://git.kernel.org/stable/c/a0b7091c4de45a7325c8780e6934a894f92ac86b