Bug 1225857 (CVE-2024-36961) - VUL-0: CVE-2024-36961: kernel: thermal/debugfs: fix two locking issues with thermal zone debug
Summary: VUL-0: CVE-2024-36961: kernel: thermal/debugfs: fix two locking issues with t...
Status: RESOLVED INVALID
Alias: CVE-2024-36961
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P3 - Medium : Normal
Target Milestone: ---
Assignee: Security Team bot
QA Contact: Security Team bot
URL: https://smash.suse.de/issue/408457/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-36961:5.3:(AV:...
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-03 15:02 UTC by SMASH SMASH
Modified: 2024-06-04 19:07 UTC (History)
2 users (show)

See Also:
Found By: Security Response Team
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---


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Description SMASH SMASH 2024-06-03 15:02:01 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
Comment 1 Miroslav Franc 2024-06-04 07:22:01 UTC
Pertains only to stable including the fix.  Nothing to do.  Switching back to security team.