AnsweredAssumed Answered

unstable MQX software using ipv6 with -Os for udp.c

Question asked by m.bach on May 8, 2015
Latest reply on Jun 19, 2015 by m.bach

Hi There,


I think I tracked down a bug in udp.c

I'm using MQX 4.1.1 along with the IPv6 Patch, and compiling RTCS with -Os

Using this, my devices crashes when receiving an IPv6 UDP multicast package, targeting a port I'm not listening to.

I will add the package 'of death' to this posting as tcpdump (pcap) file. I'm using tcpreplay to invoke the attack like this:

    $ sudo tcpreplay --intf1=eth0 ~/Desktop/ipv6_udp_multicast_crash.pcapng


This bug vanishes when wrapping an RTCS function called UDP_service6() in -O0 pragmas, like this:


#pragma GCC optimize ("O0")


void UDP_service6



#pragma GCC optimize ("Os")


Can't say what's happening exactly, and what goes south when having the complete udp.c optimized by -Os, hope I can deliver further information later on...

Does anyone have a clue, or a suggestion for me?


Thanks a lot,


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