net: qualcomm: rmnet: Fix possible null dereference in command processing

If a command packet with invalid mux id is received, the packet would
not have a valid endpoint. This invalid endpoint maybe dereferenced
leading to a crash. Identified by manual code inspection.

Fixes: 3352e6c45760 ("net: qualcomm: rmnet: Convert the muxed endpoint to hlist")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
index 6bc328f..b0dbca0 100644 (file)
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
@@ -38,6 +38,11 @@ static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
        }
 
        ep = rmnet_get_endpoint(port, mux_id);
+       if (!ep) {
+               kfree_skb(skb);
+               return RX_HANDLER_CONSUMED;
+       }
+
        vnd = ep->egress_dev;
 
        ip_family = cmd->flow_control.ip_family;