This is a note to let you know that I've just added the patch titled wifi: ath9k: htc_hst: free skb in ath9k_htc_rx_msg() if there is no callback function to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-ath9k-htc_hst-free-skb-in-ath9k_htc_rx_msg-if-t.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5ba4dd2ec5716119fc49b6a422a9555a8bcc2279 Author: Fedor Pchelkin <pchelkin@xxxxxxxxx> Date: Wed Jan 4 15:35:46 2023 +0300 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@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: syzbot+6692c72009680f7c4eb2@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Fedor Pchelkin <pchelkin@xxxxxxxxx> Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20230104123546.51427-1-pchelkin@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c index ca05b07a45e67..fe62ff668f757 100644 --- 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 @@ void ath9k_htc_rx_msg(struct htc_target *htc_handle, if (endpoint->ep_callbacks.rx) endpoint->ep_callbacks.rx(endpoint->ep_callbacks.priv, skb, epid); + else + goto invalid; } }