ext4: fix data offset overflow in ext4_xattr_fiemap() on 32-bit archs
Jan Kara [Fri, 31 May 2013 23:38:56 +0000 (19:38 -0400)]
commit a60697f411eb365fb09e639e6f183fe33d1eb796 upstream.

On 32-bit architectures with 32-bit sector_t computation of data offset
in ext4_xattr_fiemap() can overflow resulting in reporting bogus data
location. Fix the problem by typing block number to proper type before
shifting.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/extents.c

index bc0f191..e49da58 100644 (file)
@@ -4659,7 +4659,7 @@ static int ext4_xattr_fiemap(struct inode *inode,
                error = ext4_get_inode_loc(inode, &iloc);
                if (error)
                        return error;
-               physical = iloc.bh->b_blocknr << blockbits;
+               physical = (__u64)iloc.bh->b_blocknr << blockbits;
                offset = EXT4_GOOD_OLD_INODE_SIZE +
                                EXT4_I(inode)->i_extra_isize;
                physical += offset;
@@ -4667,7 +4667,7 @@ static int ext4_xattr_fiemap(struct inode *inode,
                flags |= FIEMAP_EXTENT_DATA_INLINE;
                brelse(iloc.bh);
        } else { /* external block */
-               physical = EXT4_I(inode)->i_file_acl << blockbits;
+               physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
                length = inode->i_sb->s_blocksize;
        }