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From:   Fedor Pchelkin <pchelkin@ispras.ru>
To:     =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>,
        Kalle Valo <kvalo@kernel.org>
Cc:     Fedor Pchelkin <pchelkin@ispras.ru>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Zekun Shen <bruceshenzk@gmail.com>,
        Joe Perches <joe@perches.com>,
        "John W. Linville" <linville@tuxdriver.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>,
        lvc-project@linuxtesting.org,
        syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com
Subject: [PATCH v2] wifi: ath9k: hif_usb: clean up skbs if ath9k_hif_usb_rx_stream() fails
Date:   Tue,  3 Jan 2023 17:30:29 +0300
Message-Id: <20230103143029.273695-1-pchelkin@ispras.ru>
In-Reply-To: <87h6x95huy.fsf@toke.dk>
References: 
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Syzkaller detected a memory leak of skbs in ath9k_hif_usb_rx_stream().
While processing skbs in ath9k_hif_usb_rx_stream(), the already allocated
skbs in skb_pool are not freed if ath9k_hif_usb_rx_stream() fails. If we
have an incorrect pkt_len or pkt_tag, the skb is dropped and all the
associated skb_pool buffers should be cleaned, too.

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

Fixes: 6ce708f54cc8 ("ath9k: Fix out-of-bound memcpy in ath9k_hif_usb_rx_stream")
Fixes: 44b23b488d44 ("ath9k: hif_usb: Reduce indent 1 column")
Reported-by: syzbot+e9632e3eb038d93d6bc6@syzkaller.appspotmail.com
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
v1->v2: added Reported-by tag

 drivers/net/wireless/ath/ath9k/hif_usb.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 1a2e0c7eeb02..d02cec114280 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -586,14 +586,14 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
 
 		if (pkt_tag != ATH_USB_RX_STREAM_MODE_TAG) {
 			RX_STAT_INC(hif_dev, skb_dropped);
-			return;
+			goto invalid_pkt;
 		}
 
 		if (pkt_len > 2 * MAX_RX_BUF_SIZE) {
 			dev_err(&hif_dev->udev->dev,
 				"ath9k_htc: invalid pkt_len (%x)\n", pkt_len);
 			RX_STAT_INC(hif_dev, skb_dropped);
-			return;
+			goto invalid_pkt;
 		}
 
 		pad_len = 4 - (pkt_len & 0x3);
@@ -654,6 +654,11 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
 				 skb_pool[i]->len, USB_WLAN_RX_PIPE);
 		RX_STAT_INC(hif_dev, skb_completed);
 	}
+	return;
+invalid_pkt:
+	for (i = 0; i < pool_index; i++)
+		kfree_skb(skb_pool[i]);
+	return;
 }
 
 static void ath9k_hif_usb_rx_cb(struct urb *urb)
-- 
2.34.1