After commit 8f459a072f93 ("Remove abuse of ai_canonname") the
ai_canonname field in addrinfo structs returned from
host_reliable_addrinfo() is always NULL. This causes a segfault in
check_wildcard(), breaking wildcarded client names in
/etc/exports.
The proposed solution is to add a DNS query in check_wildcard() to
obtain the client's canonical hostname on which to perform the
wildcard match.
Note that check_netgroup() probably has the same issue.
Reported-by: Mark Wagner <mark@xxxxxxxxxxx>
Fixes: 8f459a072f93 ("Remove abuse of ai_canonname")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
support/export/client.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/support/export/client.c b/support/export/client.c
index a1fba01..05260ed 100644
--- a/support/export/client.c
+++ b/support/export/client.c
@@ -608,17 +608,23 @@ check_subnetwork(const nfs_client *clp, const struct addrinfo *ai)
static int
check_wildcard(const nfs_client *clp, const struct addrinfo *ai)
{
- char *cname = clp->m_hostname;
- char *hname = ai->ai_canonname;
+ char *hname, *cname = clp->m_hostname;
struct hostent *hp;
char **ap;
- if (wildmat(hname, cname))
+ hname = host_canonname(ai->ai_addr);
+ if (hname == NULL)
+ return 0;
+
+ if (wildmat(hname, cname)) {
+ free(hname);
return 1;
+ }
/* See if hname aliases listed in /etc/hosts or nis[+]
* match the requested wildcard */
hp = gethostbyname(hname);
+ free(hname);
if (hp != NULL) {
for (ap = hp->h_aliases; *ap; ap++)
if (wildmat(*ap, cname))
