wifi: ath9k: htc_hst: free skb in ath9k_htc_rx_msg() if there is no callback function

[ Upstream commit 9b25e3985477ac3f02eca5fc1e0cc6850a3f7e69 ]

It is stated that ath9k_htc_rx_msg() either frees the provided skb or
passes its management to another callback function. However, the skb is
not freed in case there is no another callback function, and Syzkaller was
able to cause a memory leak. Also minor comment fix.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.")
Reported-by: syzbot+e008dccab31bd3647609@syzkaller.appspotmail.com
Reported-by: syzbot+6692c72009680f7c4eb2@syzkaller.appspotmail.com
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230104123546.51427-1-pchelkin@ispras.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c
index 6d69cf69fd86e1beaaee72a707d2e248c1b6efab..6331c98088e0399ba81c4813b0b6ac7ce52eaf1c 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_hst.c
+++ b/drivers/net/wireless/ath/ath9k/htc_hst.c
@@ -394,7 +394,7 @@ static void ath9k_htc_fw_panic_report(struct htc_target *htc_handle,
  * HTC Messages are handled directly here and the obtained SKB
  * is freed.
  *
- * Service messages (Data, WMI) passed to the corresponding
+ * Service messages (Data, WMI) are passed to the corresponding
  * endpoint RX handlers, which have to free the SKB.
  */
 void ath9k_htc_rx_msg(struct htc_target *htc_handle,
@@ -481,6 +481,8 @@ invalid:
                if (endpoint->ep_callbacks.rx)
                        endpoint->ep_callbacks.rx(endpoint->ep_callbacks.priv,
                                                  skb, epid);
+               else
+                       goto invalid;
        }
 }