4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Tranchetti <stranche@xxxxxxxxxxxxxx> [ Upstream commit a07f388e2cde2be74b263f85df6f672fea0305a1 ] RMNET RX handler was processing invalid packets that were originally sent on the real device and were looped back via dev_loopback_xmit(). This was detected using syzkaller. Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Sean Tranchetti <stranche@xxxxxxxxxxxxxx> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -189,6 +189,9 @@ rx_handler_result_t rmnet_rx_handler(str if (!skb) goto done; + if (skb->pkt_type == PACKET_LOOPBACK) + return RX_HANDLER_PASS; + dev = skb->dev; port = rmnet_get_port(dev);