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.
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.
On Wed, Nov 28, 2012 at 10:47:17AM +0100, Jakub Hrozek wrote:
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.
In other words, Ack.
On Sun, Dec 02, 2012 at 09:56:04PM +0100, Jakub Hrozek wrote:
On Wed, Nov 28, 2012 at 10:47:17AM +0100, Jakub Hrozek wrote:
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.
In other words, Ack.
Pushed to master and sssd-1-9
sssd-devel@lists.fedorahosted.org
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Jakub Hrozek -
Stephen Gallagher