Possible bug in openlog()

[Dima Krasner <dima@dimakrasner.com>]

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Hi,

I think I found a bug in openlog() - it's racy. If syslogd is started after openlog() is called, there's a small chance that the socket will remain open, while connect() failed. Then, syslog() does not call openlog() again, because it only checks whether the socket file descriptor is valid.

Therefore, all syslog() messages are dropped silently and nothing gets logged. I attached a fix.

Can you merge it or provide feedback, please?

Thank you,
Dima

-- 
Dima Krasner, dimakrasner.com

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diff -rup musl-1.0.4-orig/src/misc/syslog.c musl-1.0.4/src/misc/syslog.c
--- musl-1.0.4-orig/src/misc/syslog.c	2015-01-05 15:15:35.349015771 +0200
+++ musl-1.0.4/src/misc/syslog.c	2015-01-05 15:21:30.525024212 +0200
@@ -46,7 +46,11 @@ void closelog(void)
 static void __openlog()
 {
 	log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
-	if (log_fd >= 0) connect(log_fd, (void *)&log_addr, sizeof log_addr);
+	if (log_fd < 0) return;
+	if (connect(log_fd, (void *)&log_addr, sizeof log_addr) < 0) {
+		close(log_fd);
+		log_fd = -1;
+	}
 }
 
 void openlog(const char *ident, int opt, int facility)

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