From 4d9bcaddacf23861c5ee088b0c03e7034c3d59d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?=
 <ernesto.mnd.fernandez@gmail.com>
Date: Fri, 23 Jun 2017 21:37:21 -0300
Subject: [PATCH] ext2: Fix memory leak when truncate races ext2_get_blocks
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Buffer heads referencing indirect blocks may not be released if the file
is truncated at the right time. This happens because ext2_get_branch()
returns NULL when it finds the whole chain of indirect blocks already
set, and when truncate alters the chain this value of NULL is
treated as the address of the last head to be released. Handle this in the
same way as it's done after the got_it label.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext2/inode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 2dcbd56988843..30163d007b2f2 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -659,6 +659,7 @@ static int ext2_get_blocks(struct inode *inode,
 				 */
 				err = -EAGAIN;
 				count = 0;
+				partial = chain + depth - 1;
 				break;
 			}
 			blk = le32_to_cpu(*(chain[depth-1].p + count));
-- 
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