From: Kazuya Mio Date: Mon, 7 Apr 2014 14:53:28 +0000 (-0400) Subject: ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS X-Git-Tag: upstream/snapshot3+hdmi~3035 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=549b3cf1c4393f2020e375dcbf891c2c811036b8;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git 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 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 24bfd7f..b0d5860 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);