Bug 2379180 (CVE-2025-38306)

Summary: CVE-2025-38306 kernel: fs/fhandle.c: fix a race in call of has_locked_children()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-07-10 08:01:55 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fs/fhandle.c: fix a race in call of has_locked_children()

may_decode_fh() is calling has_locked_children() while holding no locks.
That's an oopsable race...

The rest of the callers are safe since they are holding namespace_sem and
are guaranteed a positive refcount on the mount in question.

Rename the current has_locked_children() to __has_locked_children(), make
it static and switch the fs/namespace.c users to it.

Make has_locked_children() a wrapper for __has_locked_children(), calling
the latter under read_seqlock_excl(&mount_lock).
Comment 1 Avinash Hanwate 2025-07-11 11:49:29 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025071014-CVE-2025-38306-66ae@gregkh/T