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

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

diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c
index ca05b07a45e67c714e58ac5f9c708acfb1b8f1c8..fe62ff668f757b621ac773e457f5c42ce7073e20 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/htc_hst.c
+++ b/drivers/net/wireless/ath/ath9k/htc_hst.c
@@ -391,7 +391,7 @@ 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,
@@ -478,6 +478,8 @@ invalid:
                if (endpoint->ep_callbacks.rx)
                        endpoint->ep_callbacks.rx(endpoint->ep_callbacks.priv,
                                                  skb, epid);
+               else
+                       goto invalid;
        }
 }