Bug 1227840 (CVE-2024-40938)

Summary: VUL-0: CVE-2024-40938: kernel: landlock: fix d_parent walk
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Miroslav Franc <miroslav.franc>
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/413865/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-40938:5.5:(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 2024-07-15 14:23:19 UTC 
In the Linux kernel, the following vulnerability has been resolved:

landlock: Fix d_parent walk

The WARN_ON_ONCE() in collect_domain_accesses() can be triggered when
trying to link a root mount point.  This cannot work in practice because
this directory is mounted, but the VFS check is done after the call to
security_path_link().

Do not use source directory's d_parent when the source directory is the
mount point.

[mic: Fix commit message]

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-40938
https://www.cve.org/CVERecord?id=CVE-2024-40938
https://git.kernel.org/stable/c/88da52ccd66e65f2e63a6c35c9dff55d448ef4dc
https://git.kernel.org/stable/c/b6e5e696435832b33e40775f060ef5c95f4fda1f
https://git.kernel.org/stable/c/c7618c7b0b8c45bcef34410cc1d1e953eb17f8f6
https://git.kernel.org/stable/c/cc30d05b34f9a087a6928d09b131f7b491e9ab11
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-40938.mbox