Root Cause

• kernel assertion messages is kernel's way representing that there is some problem here in this case its at 1193 and 1257 line from net/ipv4/tcp.c.

• In net/ipv4/tcp.c everything happening in this scenario happened in tcp_recvmsg routine.

• This routine is used to copy the data from the socket to the user buffer

- net/ipv4/tcp.c
       if (copied) {
             if (sk->sk_err ||
                 sk->sk_state == TCP_CLOSE ||
                 (sk->sk_shutdown & RCV_SHUTDOWN) ||
                 !timeo ||
                 signal_pending(current) ||
1193              (flags & MSG_PEEK))          <======
                 break;

(flags & MSG_PEEK)) checks if there is any data in the socket to copied.

The break leads us to calling the Bug trap which kernel way of handling the exception


1242             BUG_TRAP(tp->copied_seq == tp->rcv_nxt ||
                 (flags & (MSG_PEEK | MSG_TRUNC)));  <<----

• when the packet reaches the 1193 line number it checks if data lenth is zero (the data to copied to the user buffer).
• As backlog is already checked the kernel expects that there should be no data here. If the data length is not zero it enters the loop.
• Further for confirmation it finds data using (flags & MSG_PEEK) flag.Which is problem and here it calls the BugTrap.
• Now this flag MSG_PEEK is managed by the driver as the system is using HP driver we wont be able to troubleshoot it further.