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CVE-2024-36961

thermal/debugfs: Fix two locking issues with thermal zone debug PUBLISHED

Description (CNA)

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+

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 7ef01f228c9f54c6260319858be138a8a7e9e704 before 6c57bdd0505422d5ccd2df541d993aec978c842e; affected 7ef01f228c9f54c6260319858be138a8a7e9e704 before c7f7c37271787a7f77d7eedc132b0b419a76b4c8
Linux / Linuxaffected 6.8; unaffected 0 before 6.8; unaffected 6.8.10 through 6.8.*; unaffected 6.9 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CVE

No English description supplied.

CISA-ADP

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No references supplied.