s3:winbindd: fix problems with SIGCHLD handling (bug #7317)

The main problem is that we call CatchChild() within the
parent winbindd, which overwrites the signal handler
that was registered by winbindd_setup_sig_chld_handler().

That means winbindd_sig_chld_handler() and winbind_child_died()
are never triggered when a winbindd domain child dies.
As a result will get "broken pipe" for all requests to that domain.

To reduce the risk of similar bugs in future we call
CatchChild() in winbindd_reinit_after_fork() now.

We also use a full winbindd_reinit_after_fork() in the
cache validation child now instead instead of just resetting
the SIGCHLD handler by hand. This will also fix possible
tdb problems on systems without pread/pwrite and disabled mmap
as we now correctly reopen the tdb handle for the child.

metze

1 files changed, 3 insertions, 3 deletions

diff --git a/source3/winbindd/winbindd_dual.c b/source3/winbindd/winbindd_dual.c
index ca6af1f37b..eb9ace23d6 100644
--- a/source3/winbindd/winbindd_dual.c
+++ b/source3/winbindd/winbindd_dual.c
@@ -1215,6 +1215,9 @@ bool winbindd_reinit_after_fork(const char *logfilename)
 					    logfilename))
 		return false;
 
+	/* Stop zombies in children */
+	CatchChild();
+
 	/* Don't handle the same messages as our parent. */
 	messaging_deregister(winbind_messaging_context(),
 			     MSG_SMB_CONF_UPDATED, NULL);
@@ -1338,9 +1341,6 @@ static bool fork_domain_child(struct winbindd_child *child)
 
 	DEBUG(10, ("Child process %d\n", (int)sys_getpid()));
 
-	/* Stop zombies in children */
-	CatchChild();
-
 	state.sock = fdpair[0];
 	close(fdpair[1]);