From: Stelian Pop <stelian@popies.net>
Date: Thu, 1 Aug 2002 10:23:26 +0000 (+0000)
Subject: flock -> fcntl(F_SETLK).
X-Git-Tag: release_0_4b32~10
X-Git-Url: https://git.wh0rd.org/?a=commitdiff_plain;h=d86089d1dfe8565a3cf6f9d6e2fe96d29d6ab5f1;p=dump.git

flock -> fcntl(F_SETLK).
---

diff --git a/CHANGES b/CHANGES
index ff87fc8..ccd47e0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,16 @@
-$Id: CHANGES,v 1.191 2002/07/30 14:12:38 stelian Exp $
+$Id: CHANGES,v 1.192 2002/08/01 10:23:26 stelian Exp $
+
+Changes between versions 0.4b31 and 0.4b32 (released ?????????????)
+===================================================================
+
+1.	Changed dump to use fcntl(F_SETLK) style locking instead
+	of flock() when locking the dumpdates file. With the old 
+	locking scheme, a local user having read rights on the 
+	dumpdates file could be able to do a Denial of Service attack
+	on dump. In order to lock the dumpdates file with the new
+	scheme, the user would need to have write access on the file.
+	Thanks to Richard Johnson <Richard.Johnson3@ey.com> for 
+	reporting the bug (originally a bugtraq post).
 
 Changes between versions 0.4b30 and 0.4b31 (released July 30, 2002)
 ===================================================================
diff --git a/THANKS b/THANKS
index 0feb5e5..bf912f3 100644
--- a/THANKS
+++ b/THANKS
@@ -1,4 +1,4 @@
-$Id: THANKS,v 1.64 2002/07/23 12:20:35 stelian Exp $
+$Id: THANKS,v 1.65 2002/08/01 10:23:26 stelian Exp $
 
 Dump and restore were written by the people of the CSRG at the University
 of California, Berkeley.
@@ -54,6 +54,7 @@ Jean-Paul van der Jagt	jeanpaul@dutepp0.et.tudelft.nl
 Helmut Jarausch		jarausch@igpm.rwth-aachen.de
 Eric Jergensen		eric@dvns.com
 Jeff Johnson		jbj@redhat.com
+Richard Johnson		Richard.Johnson3@ey.com
 Richard Jones           rich@annexia.org
 Charles Karney		karney@users.sourceforge.net
 Henry Katz		hkatz@hkatz.dialup.access.net
diff --git a/dump/itime.c b/dump/itime.c
index 204fc58..aeaaec0 100644
--- a/dump/itime.c
+++ b/dump/itime.c
@@ -41,7 +41,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-	"$Id: itime.c,v 1.22 2002/01/25 15:08:59 stelian Exp $";
+	"$Id: itime.c,v 1.23 2002/08/01 10:23:26 stelian Exp $";
 #endif /* not lint */
 
 #include <config.h>
@@ -56,6 +56,7 @@ static const char rcsid[] =
 #include <sys/param.h>
 #include <sys/time.h>
 #include <time.h>
+#include <fcntl.h>
 #ifdef	__linux__
 #ifdef HAVE_EXT2FS_EXT2_FS_H
 #include <ext2fs/ext2_fs.h>
@@ -94,6 +95,7 @@ void
 initdumptimes(int createdumpdates)
 {
 	FILE *df;
+	struct flock lock;
 
 	if ((df = fopen(dumpdates, "r")) == NULL) {
 		if (errno != ENOENT) {
@@ -122,7 +124,11 @@ initdumptimes(int createdumpdates)
 			msg("WARNING: no file `%s'\n", dumpdates);
 	}
 	if (df != NULL) {
-		(void) flock(fileno(df), LOCK_SH);
+		memset(&lock, 0, sizeof(lock));
+		lock.l_type = F_RDLCK;
+		if (fcntl(fileno(df), F_SETLKW, &lock) < 0)
+			quit("cannot set read lock on %s: %s\n",
+				dumpdates, strerror(errno));
 		readdumptimes(df);
 		(void) fclose(df);
 	}
@@ -200,13 +206,17 @@ putdumptime(void)
 	struct dumpdates *dtwalk;
 	int i;
 	int fd;
+	struct flock lock;
 
 	if(uflag == 0)
 		return;
 	if ((df = fopen(dumpdates, "r+")) == NULL)
 		quit("cannot rewrite %s: %s\n", dumpdates, strerror(errno));
 	fd = fileno(df);
-	(void) flock(fd, LOCK_EX);
+	memset(&lock, 0, sizeof(lock));
+	lock.l_type = F_WRLCK;
+	if (fcntl(fd, F_SETLKW, &lock) < 0)
+		quit("cannot set write lock on %s: %s\n", dumpdates, strerror(errno));
 	free((char *)ddatev);
 	ddatev = 0;
 	nddates = 0;