s3: lib: Signal handling - ensure smbrun and change password code save and restore existing SIGCHLD handlers.

Bug #10831 - SIGCLD Signal handler not correctly reinstalled on old library code use - smbrun etc.

https://bugzilla.samba.org/show_bug.cgi?id=10831

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Martin Schwenke <martin@meltin.net>

2 files changed, 15 insertions, 12 deletions

diff --git a/source3/lib/smbrun.c b/source3/lib/smbrun.c
index 15a0c886e47..55f7a871d3a 100644
--- a/source3/lib/smbrun.c
+++ b/source3/lib/smbrun.c
@@ -73,6 +73,7 @@ static int smbrun_internal(const char *cmd, int *outfd, bool sanitize)
 	pid_t pid;
 	uid_t uid = current_user.ut.uid;
 	gid_t gid = current_user.ut.gid;
+	void (*saved_handler)(int);
 
 	/*
 	 * Lose any elevated privileges.
@@ -94,11 +95,11 @@ static int smbrun_internal(const char *cmd, int *outfd, bool sanitize)
 	 * SIGCLD signals as it also eats the exit status code. JRA.
 	 */
 
-	CatchChildLeaveStatus();
+	saved_handler = CatchChildLeaveStatus();
                                    	
 	if ((pid=fork()) < 0) {
 		DEBUG(0,("smbrun: fork failed with error %s\n", strerror(errno) ));
-		CatchChild(); 
+		(void)CatchSignal(SIGCLD, saved_handler);
 		if (outfd) {
 			close(*outfd);
 			*outfd = -1;
@@ -123,7 +124,7 @@ static int smbrun_internal(const char *cmd, int *outfd, bool sanitize)
 			break;
 		}
 
-		CatchChild(); 
+		(void)CatchSignal(SIGCLD, saved_handler);
 
 		if (wpid != pid) {
 			DEBUG(2,("waitpid(%d) : %s\n",(int)pid,strerror(errno)));
@@ -148,7 +149,7 @@ static int smbrun_internal(const char *cmd, int *outfd, bool sanitize)
 		return status;
 	}
 	
-	CatchChild(); 
+	(void)CatchChild();
 	
 	/* we are in the child. we exec /bin/sh to do the work for us. we
 	   don't directly exec the command we want because it may be a
@@ -237,6 +238,7 @@ int smbrunsecret(const char *cmd, const char *secret)
 	uid_t uid = current_user.ut.uid;
 	gid_t gid = current_user.ut.gid;
 	int ifd[2];
+	void (*saved_handler)(int);
 	
 	/*
 	 * Lose any elevated privileges.
@@ -257,11 +259,11 @@ int smbrunsecret(const char *cmd, const char *secret)
 	 * SIGCLD signals as it also eats the exit status code. JRA.
 	 */
 
-	CatchChildLeaveStatus();
+	saved_handler = CatchChildLeaveStatus();
                                    	
 	if ((pid=fork()) < 0) {
 		DEBUG(0, ("smbrunsecret: fork failed with error %s\n", strerror(errno)));
-		CatchChild(); 
+		(void)CatchSignal(SIGCLD, saved_handler);
 		return errno;
     	}
 
@@ -293,7 +295,7 @@ int smbrunsecret(const char *cmd, const char *secret)
 			break;
 		}
 
-		CatchChild(); 
+		(void)CatchSignal(SIGCLD, saved_handler);
 
 		if (wpid != pid) {
 			DEBUG(2, ("waitpid(%d) : %s\n", (int)pid, strerror(errno)));
@@ -309,7 +311,7 @@ int smbrunsecret(const char *cmd, const char *secret)
 		return status;
 	}
 	
-	CatchChild(); 
+	(void)CatchChild();
 	
 	/* we are in the child. we exec /bin/sh to do the work for us. we
 	   don't directly exec the command we want because it may be a
diff --git a/source3/rpc_server/samr/srv_samr_chgpasswd.c b/source3/rpc_server/samr/srv_samr_chgpasswd.c
index 1c9c33a09cf..684ccee0fb9 100644
--- a/source3/rpc_server/samr/srv_samr_chgpasswd.c
+++ b/source3/rpc_server/samr/srv_samr_chgpasswd.c
@@ -391,6 +391,7 @@ static bool chat_with_program(char *passwordprogram, const struct passwd *pass,
 	pid_t pid, wpid;
 	int wstat;
 	bool chstat = False;
+	void (*saved_handler)(int);
 
 	if (pass == NULL) {
 		DEBUG(0, ("chat_with_program: user doesn't exist in the UNIX password database.\n"));
@@ -408,13 +409,13 @@ static bool chat_with_program(char *passwordprogram, const struct passwd *pass,
 	 * SIGCLD signals as it also eats the exit status code. JRA.
 	 */
 
-	CatchChildLeaveStatus();
+	saved_handler = CatchChildLeaveStatus();
 
 	if ((pid = fork()) < 0) {
 		DEBUG(3, ("chat_with_program: Cannot fork() child for password change: %s\n", pass->pw_name));
 		SAFE_FREE(slavedev);
 		close(master);
-		CatchChild();
+		(void)CatchSignal(SIGCLD, saved_handler);
 		return (False);
 	}
 
@@ -439,14 +440,14 @@ static bool chat_with_program(char *passwordprogram, const struct passwd *pass,
 		if (wpid < 0) {
 			DEBUG(3, ("chat_with_program: The process is no longer waiting!\n\n"));
 			close(master);
-			CatchChild();
+			(void)CatchSignal(SIGCLD, saved_handler);
 			return (False);
 		}
 
 		/*
 		 * Go back to ignoring children.
 		 */
-		CatchChild();
+		(void)CatchSignal(SIGCLD, saved_handler);
 
 		close(master);