garbage is appended to /etc/resolv.conf

[gilligan]

I just wanted to update the openfortivpn package for NixOS to the latest version. Everything seemed to be working fine and I can in fact connect to our vpn. The problem is that after disconnecting VPN some garbage is being appended to /etc/resolv.conf:

^S^]AddTrust Exte<91>

As you can see in my package update PR for openfortivpn the best guess from some other contributor is that it might be some pointer corruption.

How can I provide useful information to figure out what is going on ?

[gilligan]

I ran this through valgrind - here is the output: https://gist.github.com/gilligan/f973eac77bbb87206afbc32e3eed174c

==15669== LEAK SUMMARY:
==15669==    definitely lost: 824 bytes in 1 blocks
==15669==    indirectly lost: 71,519 bytes in 653 blocks
==15669==      possibly lost: 47 bytes in 2 blocks
==15669==    still reachable: 88,011 bytes in 2,876 blocks
==15669==         suppressed: 0 bytes in 0 blocks
==15669== Reachable blocks (those to which a pointer was found) are not shown.
==15669== To see them, rerun with: --leak-check=full --show-leak-kinds=all

[gilligan]

As noted in the linked PR I notcied that there is a read happening somewhere towards the end that reads some data containing AddTrust so I'm guessing there is some memory corruption going on when the nameserver entries are removed from /etc/resolv.conf in src/ipv4.c - Can't really point at anything in specific though

[gilligan]

@adrienverge ping ;-)

[DimitriPapadopoulos]

It's a long shot, but perhaps #117 could help...

[adrienverge]

Sorry about the delay. I hope #117 will fix the problem!

[DimitriPapadopoulos]

@gilligan Does it work any better with openfortivpn 1.3.1 (which includes patch #117)?

[DimitriPapadopoulos]

I'll close this issue as #117 should have fixed the problem!