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author | Kazuya Mio <k-mio@sx.jp.nec.com> | 2014-04-07 10:53:28 -0400 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2014-04-07 10:53:28 -0400 |
commit | 4adb6ab3e0fa71363a5ef229544b2d17de6600d7 (patch) | |
tree | 3c9e190381fca754d300925d2f817ca9de53d4ad | |
parent | 666525dfbdca09bbd4848ac711e4a4dbd6921325 (diff) |
ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS
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>
Cc: stable@vger.kernel.org
-rw-r--r-- | fs/ext4/inode.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5b0d2c7d5408..93f16c5e8a8e 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -522,6 +522,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, if (unlikely(map->m_len > INT_MAX)) map->m_len = INT_MAX; + /* 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); |