[PATCH 3.11 046/131] jbd2: fix use after free in jbd2_journal_start_reserved()

[Luis Henriques]

3.11.10.6 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter at oracle.com>

commit 92e3b40537707001d17bbad800d150ab04e53bf4 upstream.

If start_this_handle() fails then it leads to a use after free of
"handle".

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso at mit.edu>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/jbd2/transaction.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index b0b74e5..7272cc6 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -514,11 +514,13 @@ int jbd2_journal_start_reserved(handle_t *handle, unsigned int type,
 	 * similarly constrained call sites
 	 */
 	ret = start_this_handle(journal, handle, GFP_NOFS);
-	if (ret < 0)
+	if (ret < 0) {
 		jbd2_journal_free_reserved(handle);
+		return ret;
+	}
 	handle->h_type = type;
 	handle->h_line_no = line_no;
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(jbd2_journal_start_reserved);
 
-- 
1.9.0