From 159499c1341f66a71d985e9b79f2131e88d1c646 Mon Sep 17 00:00:00 2001
From: Remi Pommarel <repk@triplefau.lt>
Date: Mon, 24 Mar 2025 17:28:20 +0100
Subject: [PATCH] wifi: mac80211: Update skb's control block key in
ieee80211_tx_dequeue()
[ Upstream commit a104042e2bf6528199adb6ca901efe7b60c2c27f ]
The ieee80211 skb control block key (set when skb was queued) could have
been removed before ieee80211_tx_dequeue() call. ieee80211_tx_dequeue()
already called ieee80211_tx_h_select_key() to get the current key, but
the latter do not update the key in skb control block in case it is
NULL. Because some drivers actually use this key in their TX callbacks
(e.g. ath1{1,2}k_mac_op_tx()) this could lead to the use after free
below:
BUG: KASAN: slab-use-after-free in ath11k_mac_op_tx+0x590/0x61c
Read of size 4 at addr ffffff803083c248 by task kworker/u16:4/1440
CPU: 3 UID: 0 PID: 1440 Comm: kworker/u16:4 Not tainted 6.13.0-ge128f627f404 #2
Hardware name: HW (DT)
Workqueue: bat_events batadv_send_outstanding_bcast_packet
Call trace:
show_stack+0x14/0x1c (C)
dump_stack_lvl+0x58/0x74
print_report+0x164/0x4c0
kasan_report+0xac/0xe8
__asan_report_load4_noabort+0x1c/0x24
ath11k_mac_op_tx+0x590/0x61c
ieee80211_handle_wake_tx_queue+0x12c/0x1c8
ieee80211_queue_skb+0xdcc/0x1b4c
ieee80211_tx+0x1ec/0x2bc
ieee80211_xmit+0x224/0x324
__ieee80211_subif_start_xmit+0x85c/0xcf8
ieee80211_subif_start_xmit+0xc0/0xec4
dev_hard_start_xmit+0xf4/0x28c
__dev_queue_xmit+0x6ac/0x318c
batadv_send_skb_packet+0x38c/0x4b0
batadv_send_outstanding_bcast_packet+0x110/0x328
process_one_work+0x578/0xc10
worker_thread+0x4bc/0xc7c
kthread+0x2f8/0x380
ret_from_fork+0x10/0x20
Allocated by task 1906:
kasan_save_stack+0x28/0x4c
kasan_save_track+0x1c/0x40
kasan_save_alloc_info+0x3c/0x4c
__kasan_kmalloc+0xac/0xb0
__kmalloc_noprof+0x1b4/0x380
ieee80211_key_alloc+0x3c/0xb64
ieee80211_add_key+0x1b4/0x71c
nl80211_new_key+0x2b4/0x5d8
genl_family_rcv_msg_doit+0x198/0x240
<...>
Freed by task 1494:
kasan_save_stack+0x28/0x4c
kasan_save_track+0x1c/0x40
kasan_save_free_info+0x48/0x94
__kasan_slab_free+0x48/0x60
kfree+0xc8/0x31c
kfree_sensitive+0x70/0x80
ieee80211_key_free_common+0x10c/0x174
ieee80211_free_keys+0x188/0x46c
ieee80211_stop_mesh+0x70/0x2cc
ieee80211_leave_mesh+0x1c/0x60
cfg80211_leave_mesh+0xe0/0x280
cfg80211_leave+0x1e0/0x244
<...>
Reset SKB control block key before calling ieee80211_tx_h_select_key()
to avoid that.
Fixes: bb42f2d13ffc ("mac80211: Move reorder-sensitive TX handlers to after TXQ dequeue")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Link: https://patch.msgid.link/06aa507b853ca385ceded81c18b0a6dd0f081bc8.1742833382.git.repk@triplefau.lt
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/tx.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 0ff8b56f58070..9b3a5ef20f29e 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3892,6 +3892,7 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
* The key can be removed while the packet was queued, so need to call
* this here to get the current key.
*/
+ info->control.hw_key = NULL;
r = ieee80211_tx_h_select_key(&tx);
if (r != TX_CONTINUE) {
ieee80211_free_txskb(&local->hw, skb);