This is a note to let you know that I've just added the patch titled
ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fibmap-ioctl-causes-bug_on-due-to-handle-ext_max_blocks.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4adb6ab3e0fa71363a5ef229544b2d17de6600d7 Mon Sep 17 00:00:00 2001
From: Kazuya Mio <k-mio@xxxxxxxxxxxxx>
Date: Mon, 7 Apr 2014 10:53:28 -0400
Subject: ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS
From: Kazuya Mio <k-mio@xxxxxxxxxxxxx>
commit 4adb6ab3e0fa71363a5ef229544b2d17de6600d7 upstream.
When we try to get 2^32-1 block of the file which has the extent
(ee_block=2^32-2, ee_len=1) with FIBMAP ioctl, it causes BUG_ON
in ext4_ext_put_gap_in_cache().
To avoid the problem, ext4_map_blocks() needs to check the file logical block
number. ext4_ext_put_gap_in_cache() called via ext4_map_blocks() cannot
handle 2^32-1 because the maximum file logical block number is 2^32-2.
Note that ext4_ind_map_blocks() returns -EIO when the block number is invalid.
So ext4_map_blocks() should also return the same errno.
Signed-off-by: Kazuya Mio <k-mio@xxxxxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -515,6 +515,10 @@ int ext4_map_blocks(handle_t *handle, st
"logical block %lu\n", inode->i_ino, flags, map->m_len,
(unsigned long) map->m_lblk);
+ /* We can handle the block number less than EXT_MAX_BLOCKS */
+ if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
+ return -EIO;
+
/* Lookup extent status tree firstly */
if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
ext4_es_lru_add(inode);
Patches currently in stable-queue which might be from k-mio@xxxxxxxxxxxxx are
queue-3.14/ext4-fibmap-ioctl-causes-bug_on-due-to-handle-ext_max_blocks.patch
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