3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: "holger@xxxxxxxxxxxxxxxx" <holger@xxxxxxxxxxxxxxxx> [ Upstream commit c5060cec6ba27ad3f0e7facfdf05d2f18e3e3010 ] There is bug in the receive path of the asix driver at the time a packet is received larger than MTU size and DF bit set: BUG: unable to handle kernel paging request at 0000004000000001 IP: [<ffffffff8126f65b>] skb_release_head_state+0x2d/0xd2 ... Call Trace: <IRQ> [<ffffffff8126f86d>] ? skb_release_all+0x9/0x1e [<ffffffff8126f8ad>] ? __kfree_skb+0x9/0x6f [<ffffffffa00b4200>] ? asix_rx_fixup_internal+0xff/0x1ae [asix] [<ffffffffa00fb3dc>] ? usbnet_bh+0x4f/0x226 [usbnet] ... It is easily reproducable by setting an MTU of 512 e. g. and sending something like ping -s 1472 -c 1 -M do $SELF from another box. And this is because the rx->ax_skb is freed on error, but rx->ax_skb is not reset, and the size is not reset to zero in this case. And since the skb is added again to the usbnet->done skb queue it is accessing already freed memory, resulting in the BUG when freeing a 2nd time. I therefore think the value 0x0000004000000001 show in the trace is more or less random data. Signed-off-by: Holger Eitzenberger <holger@xxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/usb/asix_common.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/usb/asix_common.c +++ b/drivers/net/usb/asix_common.c @@ -100,6 +100,9 @@ int asix_rx_fixup_internal(struct usbnet netdev_err(dev->net, "asix_rx_fixup() Bad RX Length %d\n", rx->size); kfree_skb(rx->ax_skb); + rx->ax_skb = NULL; + rx->size = 0U; + return 0; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html