wifi: ath9k: hif_usb: clean up skbs if ath9k_hif_usb_rx_stream() fails

[ Upstream commit 0af54343a76263a12dbae7fafb64eb47c4a6ad38 ]

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 input skb is considered invalid
and dropped. All the associated packets already in skb_pool should be
dropped and freed. Added a comment describing this issue.

The patch also makes remain_skb NULL after being processed so that it
cannot be referenced after potential free. The initialization of hif_dev
fields which are associated with remain_skb (rx_remain_len,
rx_transfer_len and rx_pad_len) is moved after a new remain_skb is
allocated.

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

Fixes: 6ce708f54cc8 ("ath9k: Fix out-of-bound memcpy in ath9k_hif_usb_rx_stream")
Fixes: 44b23b488d ("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>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230104123615.51511-1-pchelkin@ispras.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Fedor Pchelkin 2023-01-04 15:36:15 +03:00 committed by Greg Kroah-Hartman
parent c3ff385b94
commit cd83167670

View File

@ -561,11 +561,11 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
memcpy(ptr, skb->data, rx_remain_len);
rx_pkt_len += rx_remain_len;
hif_dev->rx_remain_len = 0;
skb_put(remain_skb, rx_pkt_len);
skb_pool[pool_index++] = remain_skb;
hif_dev->remain_skb = NULL;
hif_dev->rx_remain_len = 0;
} else {
index = rx_remain_len;
}
@ -584,16 +584,21 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
pkt_len = get_unaligned_le16(ptr + index);
pkt_tag = get_unaligned_le16(ptr + index + 2);
/* It is supposed that if we have an invalid pkt_tag or
* pkt_len then the whole input SKB is considered invalid
* and dropped; the associated packets already in skb_pool
* are dropped, too.
*/
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);
@ -605,11 +610,6 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
if (index > MAX_RX_BUF_SIZE) {
spin_lock(&hif_dev->rx_lock);
hif_dev->rx_remain_len = index - MAX_RX_BUF_SIZE;
hif_dev->rx_transfer_len =
MAX_RX_BUF_SIZE - chk_idx - 4;
hif_dev->rx_pad_len = pad_len;
nskb = __dev_alloc_skb(pkt_len + 32, GFP_ATOMIC);
if (!nskb) {
dev_err(&hif_dev->udev->dev,
@ -617,6 +617,12 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
spin_unlock(&hif_dev->rx_lock);
goto err;
}
hif_dev->rx_remain_len = index - MAX_RX_BUF_SIZE;
hif_dev->rx_transfer_len =
MAX_RX_BUF_SIZE - chk_idx - 4;
hif_dev->rx_pad_len = pad_len;
skb_reserve(nskb, 32);
RX_STAT_INC(hif_dev, skb_allocated);
@ -654,6 +660,13 @@ err:
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++) {
dev_kfree_skb_any(skb_pool[i]);
RX_STAT_INC(hif_dev, skb_dropped);
}
return;
}
static void ath9k_hif_usb_rx_cb(struct urb *urb)