From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Fri, 23 Apr 2010 09:56:24 +0000 (-0400)
Subject: Lock the tty timestamp when writing.  We shouldn't have to lock when
X-Git-Tag: SUDO_1_8_0~703
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f7f9def5ef7bf6c0d02a4d6c7c4f0402d83a4e93;p=sudo

Lock the tty timestamp when writing.  We shouldn't have to lock when
reading since the file is updated via a single write system call.
---

diff --git a/plugins/sudoers/check.c b/plugins/sudoers/check.c
index 1e6d4c2c3..7ad06eeac 100644
--- a/plugins/sudoers/check.c
+++ b/plugins/sudoers/check.c
@@ -230,10 +230,11 @@ update_timestamp(char *timestampdir, char *timestampfile)
 	/*
 	 * Store tty info in timestamp file
 	 */
-	int fd = open(timestampfile, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+	int fd = open(timestampfile, O_WRONLY|O_CREAT, 0600);
 	if (fd == -1)
 	    log_error(NO_EXIT|USE_ERRNO, "Can't open %s", timestampfile);
 	else {
+	    lock_file(fd, SUDO_LOCK);
 	    write(fd, &tty_info, sizeof(tty_info));
 	    close(fd);
 	}