From 9480adfe4e0f0319b9da04b44e4eebd5ad07e0cd Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 29 Jan 2024 15:53:48 +0100
Subject: [PATCH] wifi: mac80211: fix RCU use in TDLS fast-xmit
Git-commit: 9480adfe4e0f0319b9da04b44e4eebd5ad07e0cd
Patch-mainline: v6.8-rc4
References: git-fixes CVE-2024-26666 bsc#1222293
This looks up the link under RCU protection, but isn't
guaranteed to actually have protection. Fix that.
Fixes: 8cc07265b691 ("wifi: mac80211: handle TDLS data frames with MLO")
Link: https://msgid.link/20240129155348.8a9c0b1e1d89.I553f96ce953bb41b0b877d592056164dec20d01c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/mac80211/tx.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 68a48abc7287..e448ab338448 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3100,10 +3100,11 @@ void ieee80211_check_fast_xmit(struct sta_info *sta)
/* DA SA BSSID */
build.da_offs = offsetof(struct ieee80211_hdr, addr1);
build.sa_offs = offsetof(struct ieee80211_hdr, addr2);
+ rcu_read_lock();
link = rcu_dereference(sdata->link[tdls_link_id]);
- if (WARN_ON_ONCE(!link))
- break;
- memcpy(hdr->addr3, link->u.mgd.bssid, ETH_ALEN);
+ if (!WARN_ON_ONCE(!link))
+ memcpy(hdr->addr3, link->u.mgd.bssid, ETH_ALEN);
+ rcu_read_unlock();
build.hdr_len = 24;
break;
}
--
2.35.3