net: qualcomm: rmnet: Skip processing loopback packets

[ 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@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 929fb8d96ec0ced8ddb36f52477c28344e71ba38..8d979fef5fc725177bf094aeeb253aa11daf675f 100644 (file)
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -205,6 +205,9 @@ rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb)
        if (!skb)
                return RX_HANDLER_CONSUMED;
 
+       if (skb->pkt_type == PACKET_LOOPBACK)
+               return RX_HANDLER_PASS;
+
        dev = skb->dev;
        port = rmnet_get_port(dev);