[PATCH] gssd: don't let spurious signals interrupt the wait after forking

[Jeff Layton <jlayton@redhat.com>]

Because gssd uses dnotify under the hood, it's easily possible that the
parent process can catch a signal while processing an upcall. If that
happens, then we'll currently exit the wait for the child task to exit,
and it'll end up as a zombie.

Fix this by ensuring that we only wait for the child to actually exit.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 utils/gssd/gssd_proc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index b48d163..447aec1 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -1040,7 +1040,10 @@ process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd, char *tgtname,
 		return;
 	default:
 		/* Parent: just wait on child to exit and return */
-		wait(&err);
+		do {
+			pid = wait(&err);
+		} while(pid == -1 && errno != -ECHILD);
+
 		if (WIFSIGNALED(err))
 			printerr(0, "WARNING: forked child was killed with signal %d\n",
 					WTERMSIG(err));
-- 
1.8.3.1