wifi: mac80211: fix mesh fast xmit path deletion UAF

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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.

Fixes: d5edb9ae8d ("wifi: mac80211: mesh fast xmit support")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: LLM
Co-developed-by: Luxing Yin <root@tr0jan.top>
Signed-off-by: Luxing Yin <root@tr0jan.top>
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Link: https://patch.msgid.link/1daa7a98199fe6965c2da7c42717073a6fd39a0b.1789615568.git.zihanx@nebusec.ai
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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Zihan Xi 2026-09-18 05:26:51 +00:00 • committed by Johannes Berg

parent 5e4f350979

commit ee3aadc43e

1 changed files with 11 additions and 1 deletions

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net/mac80211/mesh_pathtbl.c

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