Bug 1224708 (CVE-2024-35793)

Summary: VUL-0: CVE-2024-35793: kernel: debugfs: fix wait/cancellation handling during remove
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: RESOLVED FIXED QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: gabriele.sonnu, jlee
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/406372/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-35793:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-05-20 16:08:11 UTC 
In the Linux kernel, the following vulnerability has been resolved:

debugfs: fix wait/cancellation handling during remove

Ben Greear further reports deadlocks during concurrent debugfs
remove while files are being accessed, even though the code in
question now uses debugfs cancellations. Turns out that despite
all the review on the locking, we missed completely that the
logic is wrong: if the refcount hits zero we can finish (and
need not wait for the completion), but if it doesn't we have
to trigger all the cancellations. As written, we can _never_
get into the loop triggering the cancellations. Fix this, and
explain it better while at it.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-35793
https://www.cve.org/CVERecord?id=CVE-2024-35793
https://git.kernel.org/stable/c/3d08cca5fd0aabb62b7015067ab40913b33da906
https://git.kernel.org/stable/c/952c3fce297f12c7ff59380adb66b564e2bc9b64
https://git.kernel.org/stable/c/e88b5ae01901c4a655a53158397746334778a57b
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-35793.mbox
https://bugzilla.redhat.com/show_bug.cgi?id=2281047
Comment 1 Joey Lee 2024-05-21 07:03:54 UTC 
https://www.suse.com/security/cve/CVE-2024-35793.html
cvss 5.5
Comment 2 Joey Lee 2024-05-23 12:19:45 UTC 
joeyli@linux-691t:/mnt/working/source_code-git/kernel-source> ./scripts/check-kernel-fix CVE-2024-35793
952c3fce297f ("debugfs: fix wait/cancellation handling during remove") merged v6.9-rc1~34^2~6
Fixes: 8c88a474357e ("debugfs: add API to allow debugfs operations cancellation") merged v6.7-rc4~22^2~3^2~3
Security fix for CVE-2024-35793 bsc#1224708 with CVSS 5.5
Experts candidates: fdmanana@suse.de dsterba@suse.cz jack@suse.cz rgoldwyn@suse.de ddiss@suse.de krisman@suse.de 
..............................
NO ACTION NEEDED: All relevant branches contain the fix!

Does not affect any branch. reset assignee
Comment 3 Gabriele Sonnu 2024-06-10 12:24:29 UTC 
All done, closing.