[PATCH 5.4 145/165] net: usb: lan78xx: fix possible skb leak

Greg Kroah-Hartman
2020-01-11T10:33:08Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 47240ba0cd09bb6fe6db9889582048324999dfa4 ]

If skb_linearize() fails, we need to free the skb.

TSO makes skb bigger, and this bug might be the reason
Raspberry Pi 3B+ users had to disable TSO.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: RENARD Pierre-Francois <pfrenard@gmail.com>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Cc: Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/usb/lan78xx.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2724,11 +2724,6 @@ static int lan78xx_stop(struct net_devic
return 0;
}

-static int lan78xx_linearize(struct sk_buff *skb)
-{
- return skb_linearize(skb);
-}
-
static struct sk_buff *lan78xx_tx_prep(struct lan78xx_net *dev,
struct sk_buff *skb, gfp_t flags)
{
@@ -2740,8 +2735,10 @@ static struct sk_buff *lan78xx_tx_prep(s
return NULL;
}

- if (lan78xx_linearize(skb) < 0)
+ if (skb_linearize(skb)) {
+ dev_kfree_skb_any(skb);
return NULL;
+ }

tx_cmd_a = (u32)(skb->len & TX_CMD_A_LEN_MASK_) | TX_CMD_A_FCS_;