From: Eric Sandeen <sandeen@redhat.com>
Date: Fri, 16 Sep 2011 20:49:21 +0000 (-0500)
Subject: libext2fs: Potential null ptr deref in undo_err_handler_init
X-Git-Tag: v1.42-WIP-0925~34
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=665563b825ca697a2b4bdd340760a36f6263709e;p=tools%2Fe2fsprogs.git

libext2fs: Potential null ptr deref in undo_err_handler_init

In the !undo_io_backing_manager case, undo_err_handler_init
will be passed a null data->real, which will be dereferenced.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/lib/ext2fs/undo_io.c b/lib/ext2fs/undo_io.c
index 454f3b6..da1cf45 100644
--- a/lib/ext2fs/undo_io.c
+++ b/lib/ext2fs/undo_io.c
@@ -400,7 +400,8 @@ static errcode_t undo_open(const char *name, int flags, io_channel *channel)
 	 * setup err handler for read so that we know
 	 * when the backing manager fails do short read
 	 */
-	undo_err_handler_init(data->real);
+	if (data->real)
+		undo_err_handler_init(data->real);
 
 	*channel = io;
 	return 0;