[SSSD] [PATCH] IPA: Handle bad results from c-ares lookup

Jakub Hrozek jhrozek at redhat.com
Wed Nov 28 09:47:17 UTC 2012


On Tue, Nov 27, 2012 at 04:10:23PM -0500, Stephen Gallagher wrote:
> In some situations, the c-ares lookup can return NULL instead of
> a list of addresses. In this situation, we need to avoid
> dereferencing NULL.
> 
> This patch adds a log message and sets the count to zero so it is
> handled appropriately below.
> 
> This patch fixes the crash seen in
> https://bugzilla.redhat.com/show_bug.cgi?id=880571
> 
> This may actually be due to a bug in c-ares, but we should be
> defensive anyway.

I wonder if it may be better to perform this check at the resolver
level, maybe in resolv_gethostbyname_dns_parse() check out the hostent
structure and if it's present but empty then return ENOENT.

The patch is fine, though and we can commit it as well. It doesn't hurt
to have additional checks.



More information about the sssd-devel mailing list