[PATCH] net: usb: asix: Fix crash on skb alloc failure

From: David B. Robins
Date: Wed Sep 30 2015 - 16:07:42 EST


If asix_rx_fixup_internal() fails to allocate rx->ax_skb, it will return
but not clear rx->size. rx points to driver private data. A later call
assumes that nonzero size means ax_skb was allocated and passes a null
ax_skb to skb_put. Changed allocation failure return to clear size first.

Found testing board with AX88772B devices.

Signed-off-by: David B. Robins <linux@xxxxxxxxxxxxxxx>
---
drivers/net/usb/asix_common.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c
index 75d6f26..079069a 100644
--- a/drivers/net/usb/asix_common.c
+++ b/drivers/net/usb/asix_common.c
@@ -91,8 +91,10 @@ int asix_rx_fixup_internal(struct usbnet *dev, struct sk_buff *skb,
}
rx->ax_skb = netdev_alloc_skb_ip_align(dev->net,
rx->size);
- if (!rx->ax_skb)
+ if (!rx->ax_skb) {
+ rx->size = 0;
return 0;
+ }
}

if (rx->size > dev->net->mtu + ETH_HLEN + VLAN_HLEN) {
--
1.9.1

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