[BusyBox] [PATCH] mount -a -t nfs causes a segmentation fault

[YAEGASHI Takeshi]

Hi,

With the following /etc/fstab (any two or more lines of nfs), mount -a
-t nfs causes a segmentation faults.

server:/exports/aaa /mnt/aaa nfs defaults 0 0
server:/exprots/bbb /mnt/bbb nfs defaults 0 0

In util-linux/nfsmount.c, it overwrites malloc'ed pointer *mount_opts
with a static pointer.  With this patch it does proper memory realloc
and data copy instead.


Index: util-linux/nfsmount.c
===================================================================
RCS file: /var/cvs/busybox/util-linux/nfsmount.c,v
retrieving revision 1.27
diff -u -r1.27 nfsmount.c
--- util-linux/nfsmount.c	15 Mar 2004 08:29:22 -0000	1.27
+++ util-linux/nfsmount.c	26 Jul 2004 08:39:23 -0000
@@ -315,7 +315,7 @@
 	char new_opts[1024];
 	struct timeval total_timeout;
 	enum clnt_stat clnt_stat;
-	static struct nfs_mount_data data;
+	struct nfs_mount_data data;
 	char *opt, *opteq;
 	int val;
 	struct hostent *hp;
@@ -602,10 +602,9 @@
 #endif
 
 	data.version = nfs_mount_version;
-	*mount_opts = (char *) &data;
 
 	if (*flags & MS_REMOUNT)
-		return 0;
+		goto copy_data_and_return;
 
 	/*
 	 * If the previous mount operation on the same host was
@@ -857,6 +856,9 @@
 	auth_destroy(mclient->cl_auth);
 	clnt_destroy(mclient);
 	close(msock);
+copy_data_and_return:
+	*mount_opts = xrealloc(*mount_opts, sizeof(data));
+	memcpy(*mount_opts, &data, sizeof(data));
 	return 0;
 
 	/* abort */

Regards,
--
YAEGASHI Takeshi <t at keshi.org> <takeshi at yaegashi.jp>