[lwip-users] [LwIP 1.4.1] Ping length of 92 bytes via PPP crashes LwIP core/pbuf.c

[Marco Jakobs]

Hi,

 

during a test we ran into a serious issue and I'd be more than happy to get some hints how to track that down.

 

In a test scenario we ran a ping test with various byte sizes via the PPP netif. With exactly the ping packet size of 92 bytes, our LwIP task crashes repeatedly into an assert:

 

15.05.17 11:07:17 ASSERT: C:/Projekte/TMO-100/Libraries/lwIP/src/core/pbuf.c:888:p_to != NULL

 

The line where this happens is line 888 in pbuf.c:

 

    if (offset_to == p_to->len) {

      /* on to next p_to (if any) */

      offset_to = 0;

      p_to = p_to->next;

      LWIP_ERROR("p_to != NULL", (p_to != NULL) || (p_from == NULL) , return ERR_ARG;);

    }

 

It's strange that this does not happen if the ping comes via the ETH netif, it only occurs via the PPP netif.

 

Any ideas where to start debugging is welcome ;-)

 

Thanks,

Marco