Bug 1227781 (CVE-2024-40920)

Summary: VUL-0: CVE-2024-40920: kernel: net: bridge: mst: fix suspicious rcu usage in br_mst_set_state
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Michal Kubeček <mkubecek>
Status: NEW --- QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: camila.matos, miroslav.franc
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/413847/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-40920:5.5:(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: ---
Bug Depends on: 1226604    
Bug Blocks:    

Description SMASH SMASH 2024-07-15 11:15:39 UTC
In the Linux kernel, the following vulnerability has been resolved:

net: bridge: mst: fix suspicious rcu usage in br_mst_set_state

I converted br_mst_set_state to RCU to avoid a vlan use-after-free
but forgot to change the vlan group dereference helper. Switch to vlan
group RCU deref helper to fix the suspicious rcu usage warning.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-40920
https://www.cve.org/CVERecord?id=CVE-2024-40920
https://git.kernel.org/stable/c/406bfc04b01ee47e4c626f77ecc7d9f85135b166
https://git.kernel.org/stable/c/546ceb1dfdac866648ec959cbc71d9525bd73462
https://git.kernel.org/stable/c/7caefa2771722e65496d85b62e1dc4442b7d1345
https://git.kernel.org/stable/c/caaa2129784a04dcade0ea92c12e6ff90bbd23d8
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-40920.mbox