diff options
| author | Kazuya Mio <k-mio@sx.jp.nec.com> | 2014-04-07 10:53:28 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-05-18 14:58:02 +0100 |
| commit | 5e76e584d0b4e24eed04871d807b3081e97bcfb2 (patch) | |
| tree | cb8f1ec3c4a71bcca457dd364e1d830958f2127a | |
| parent | f453538a1f5b66168caf9c446c56375246b4ac29 (diff) | |
ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS
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@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | fs/ext4/inode.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index dc9f0ecd8f4..55d4f461992 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -481,6 +481,11 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," "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; + /* * Try to see if we can get the block without requesting a new * file system block. |