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authorKazuya Mio <k-mio@sx.jp.nec.com>2014-04-07 10:53:28 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-06 07:59:36 -0700
commit549b3cf1c4393f2020e375dcbf891c2c811036b8 (patch)
tree0ea8745344e8413fdd834b24c26a9989f13dcf2a /fs
parentb4140e2b766bb20f0eb9d363be9072905977c5e0 (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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/inode.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 24bfd7ff3049..b0d5860c0e50 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -515,6 +515,10 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
"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);