linux-kernel - [ 050/104] ext4: fix the wrong number of the allocated blocks in

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20130325010529.244383592@decadent.org.uk>
Date:	Mon, 25 Mar 2013 01:06:14 +0000
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	akpm@...ux-foundation.org, Zheng Liu <wenqing.lz@...bao.com>,
	"Theodore Tso" <tytso@....edu>,
	Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [ 050/104] ext4: fix the wrong number of the allocated blocks in

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

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

From: Zheng Liu <wenqing.lz@...bao.com>

commit 3a2256702e47f68f921dfad41b1764d05c572329 upstream.

This commit fixes a wrong return value of the number of the allocated
blocks in ext4_split_extent.  When the length of blocks we want to
allocate is greater than the length of the current extent, we return a
wrong number.  Let's see what happens in the following case when we
call ext4_split_extent().

  map: [48, 72]
  ex:  [32, 64, u]

'ex' will be split into two parts:
  ex1: [32, 47, u]
  ex2: [48, 64, w]

'map->m_len' is returned from this function, and the value is 24.  But
the real length is 16.  So it should be fixed.

Meanwhile in this commit we use right length of the allocated blocks
when get_reserved_cluster_alloc in ext4_ext_handle_uninitialized_extents
is called.

Signed-off-by: Zheng Liu <wenqing.lz@...bao.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
Cc: Dmitry Monakhov <dmonakhov@...nvz.org>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 fs/ext4/extents.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2960,6 +2960,7 @@ static int ext4_split_extent(handle_t *h
 	int err = 0;
 	int uninitialized;
 	int split_flag1, flags1;
+	int allocated = map->m_len;
 
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
@@ -2979,6 +2980,8 @@ static int ext4_split_extent(handle_t *h
 				map->m_lblk + map->m_len, split_flag1, flags1);
 		if (err)
 			goto out;
+	} else {
+		allocated = ee_len - (map->m_lblk - ee_block);
 	}
 
 	ext4_ext_drop_refs(path);
@@ -3001,7 +3004,7 @@ static int ext4_split_extent(handle_t *h
 
 	ext4_ext_show_leaf(inode, path);
 out:
-	return err ? err : map->m_len;
+	return err ? err : allocated;
 }
 
 #define EXT4_EXT_ZERO_LEN 7
@@ -3663,6 +3666,7 @@ out:
 					allocated - map->m_len);
 		allocated = map->m_len;
 	}
+	map->m_len = allocated;
 
 	/*
 	 * If we have done fallocate with the offset that is already


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/