Bug 2555101 (CVE-2026-98699)

Summary: CVE-2026-98699 kernel: wifi: mac80211: fix mesh fast xmit path deletion UAF
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: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's mac80211 wireless subsystem. A race condition occurs during mesh network path deletion when an active lookup reinserts an entry into the fast transmission cache after the cache has been cleared, resulting in a use-after-free condition where memory is accessed after being released. An attacker could exploit this flaw to cause a Denial of Service (DoS) by crashing the system or potentially achieve arbitrary code execution.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-18 15:54:29 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211: fix mesh fast xmit path deletion UAF

mesh_fast_tx_cache() stores raw mesh_path pointers. Path deletion
flushes the cache and then frees the path with kfree_rcu(), but a
lookup that already holds the path can insert a new cache entry
after the flush. The cache then points at freed memory.

Set MESH_PATH_DELETED before flushing, and skip inserting a cache
entry if the path or MPP path is already deleted. Check this under
the cache walk lock so it is ordered with the flush. Use WRITE_ONCE()
for the deletion flag updates because the cache check reads flags
without taking state_lock.
Comment 1 Mauro Matteo Cascella 2026-10-22 04:56:35 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98699.mbox