From: Jim Baxter <jim_baxter@xxxxxxxxxx> "Unable to handle kernel NULL pointer dereference at virtual address 00000078" is reported with "PC is at eth_start_xmit+0x19c/0x378 [u_ether]" The failure scenario is seen when closing the NCM connection while the TCP/IPv6 stack is still trying to transmit over NCM. Defensive code is missing from commit 6d3865f9d41f15ddbcecaa6722871fc0db21d7ab "usb: gadget: NCM: Add transmit multi-frame." Add check for non-NULL dev->port_usb before accessing dev->port_usb->supports_multi_frame. Signed-off-by: Mark Craske <Mark_Craske@xxxxxxxxxx> Signed-off-by: Jim Baxter <jim_baxter@xxxxxxxxxx> --- drivers/usb/gadget/function/u_ether.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 637809e..68f0b7b 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -556,7 +556,8 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, /* Multi frame CDC protocols may store the frame for * later which is not a dropped frame. */ - if (dev->port_usb->supports_multi_frame) + if (dev->port_usb && + dev->port_usb->supports_multi_frame) goto multiframe; goto drop; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
