Bugzilla – Bug 1225857
VUL-0: CVE-2024-36961: kernel: thermal/debugfs: fix two locking issues with thermal zone debug
Last modified: 2024-06-04 19:07:20 UTC
In the Linux kernel, the following vulnerability has been resolved: thermal/debugfs: Fix two locking issues with thermal zone debug With the current thermal zone locking arrangement in the debugfs code, user space can open the "mitigations" file for a thermal zone before the zone's debugfs pointer is set which will result in a NULL pointer dereference in tze_seq_start(). Moreover, thermal_debug_tz_remove() is not called under the thermal zone lock, so it can run in parallel with the other functions accessing the thermal zone's struct thermal_debugfs object. Then, it may clear tz->debugfs after one of those functions has checked it and the struct thermal_debugfs object may be freed prematurely. To address the first problem, pass a pointer to the thermal zone's struct thermal_debugfs object to debugfs_create_file() in thermal_debug_tz_add() and make tze_seq_start(), tze_seq_next(), tze_seq_stop(), and tze_seq_show() retrieve it from s->private instead of a pointer to the thermal zone object. This will ensure that tz_debugfs will be valid across the "mitigations" file accesses until thermal_debugfs_remove_id() called by thermal_debug_tz_remove() removes that file. To address the second problem, use tz->lock in thermal_debug_tz_remove() around the tz->debugfs value check (in case the same thermal zone is removed at the same time in two different threads) and its reset to NULL. Cc :6.8+ <stable@vger.kernel.org> # 6.8+ References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-36961 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-36961.mbox https://git.kernel.org/stable/c/6c57bdd0505422d5ccd2df541d993aec978c842e https://git.kernel.org/stable/c/c7f7c37271787a7f77d7eedc132b0b419a76b4c8 https://www.cve.org/CVERecord?id=CVE-2024-36961
Pertains only to stable including the fix. Nothing to do. Switching back to security team.