[Dnsmasq-discuss] CNAME related segfault in v2.67 onwards

[Andrew Childs]

Hi,

On 26/11/2013, at 3:19 am, Simon Kelley <simon at thekelleys.org.uk> wrote:

> Many thanks for the thorough analysis. My understanding is that this is fixed in
> 
> http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=7b174c250df2bc97b503fd03b9e473998676b1a6
> 
> and therefore in 2.68test1 onwards. The Subject of your email implies that's not true, or have I misunderstood?

I’m still seeing this crash in v2.68rc2. There’s a check in cache_find_by_name (cache.c:561) that doesn’t consider F_CONFIG. Here’s a full backtrace from v2.68rc2:

(gdb) run -d -C dnsmasq.conf
Starting program: /usr/home/lorne/dnsmasq/src/dnsmasq -d -C dnsmasq.conf
dnsmasq: started, version 2.68rc2 cachesize 150
dnsmasq: compile time options: IPv6 GNU-getopt no-DBus i18n IDN DHCP DHCPv6 no-Lua TFTP no-conntrack no-ipset auth
dnsmasq: reading resolv.conf
dnsmasq: using nameserver 8.8.8.8#53
dnsmasq: read dnsmasq-hosts - 2 addresses

Program received signal SIGSEGV, Segmentation fault.
0x00000000004037a4 in cache_unlink (crecp=0x80146f580) at cache.c:221
(gdb) bt
#0  0x00000000004037a4 in cache_unlink (crecp=0x80146f580) at cache.c:221
#1  0x000000000040425c in cache_find_by_name (crecp=0x80146f580, name=0x801409100 "a", now=1385403233, prot=2176)
    at cache.c:568
#2  0x000000000040bfda in answer_request (header=0x80142d000, limit=0x80142d200 "", qlen=19, local_addr=...,
    local_netmask=..., now=1385403233) at rfc1035.c:1761
#3  0x000000000041b891 in receive_query (listen=0x801407100, now=1385403233) at forward.c:893
#4  0x0000000000422396 in check_dns_listeners (set=0x7fffffffd450, now=1385403233) at dnsmasq.c:1375
#5  0x0000000000421139 in main (argc=4, argv=0x7fffffffd6a0) at dnsmasq.c:904

Thanks,
Andrew

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