This is a note to let you know that I've just added the patch titled
net: usb: smsc75xx: Move packet length check to prevent kernel panic in skb_pull
to the 4.19-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:
net-usb-smsc75xx-move-packet-length-check-to-prevent.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dcd96f9b2f35f0268df8a7130c7830e26dfe7505
Author: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
Date: Thu Mar 16 12:05:40 2023 +0100
net: usb: smsc75xx: Move packet length check to prevent kernel panic in skb_pull
[ Upstream commit 43ffe6caccc7a1bb9d7442fbab521efbf6c1378c ]
Packet length check needs to be located after size and align_count
calculation to prevent kernel panic in skb_pull() in case
rx_cmd_a & RX_CMD_A_RED evaluates to true.
Fixes: d8b228318935 ("net: usb: smsc75xx: Limit packet length to skb->len")
Signed-off-by: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230316110540.77531-1-szymon.heidrich@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index b4705dee2b751..313a4b0edc6b3 100644
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -2213,6 +2213,13 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
size = (rx_cmd_a & RX_CMD_A_LEN) - RXW_PADDING;
align_count = (4 - ((size + RXW_PADDING) % 4)) % 4;
+ if (unlikely(size > skb->len)) {
+ netif_dbg(dev, rx_err, dev->net,
+ "size err rx_cmd_a=0x%08x\n",
+ rx_cmd_a);
+ return 0;
+ }
+
if (unlikely(rx_cmd_a & RX_CMD_A_RED)) {
netif_dbg(dev, rx_err, dev->net,
"Error rx_cmd_a=0x%08x\n", rx_cmd_a);
@@ -2225,8 +2232,7 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
dev->net->stats.rx_frame_errors++;
} else {
/* MAX_SINGLE_PACKET_SIZE + 4(CRC) + 2(COE) + 4(Vlan) */
- if (unlikely(size > (MAX_SINGLE_PACKET_SIZE + ETH_HLEN + 12) ||
- size > skb->len)) {
+ if (unlikely(size > (MAX_SINGLE_PACKET_SIZE + ETH_HLEN + 12))) {
netif_dbg(dev, rx_err, dev->net,
"size err rx_cmd_a=0x%08x\n",
rx_cmd_a);
