Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e7293fd1 authored by Jan Kara's avatar Jan Kara Committed by Theodore Ts'o
Browse files

ext4: fix overflows in SEEK_HOLE, SEEK_DATA implementations 



ext4_lblk_t is just u32 so multiplying it by blocksize can easily
overflow for files larger than 4 GB. Fix that by properly typing the
block offsets before shifting.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarZheng Liu <wenqing.lz@taobao.com>
parent eaf37937

fs/ext4/file.c

+7 −7
Original line number Diff line number Diff line
@@ -312,7 +312,7 @@ static int ext4_find_unwritten_pgoff(struct inode *inode, 
	blkbits = inode->i_sb->s_blocksize_bits;

	startoff = *offset;

	lastoff = startoff;

	endoff = (map->m_lblk + map->m_len) << blkbits;

	endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits;



	index = startoff >> PAGE_CACHE_SHIFT;

	end = endoff >> PAGE_CACHE_SHIFT;
@@ -457,7 +457,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) 
		ret = ext4_map_blocks(NULL, inode, &map, 0);

		if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {

			if (last != start)

				dataoff = last << blkbits;

				dataoff = (loff_t)last << blkbits;

			break;

		}
@@ -468,7 +468,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) 
		ext4_es_find_delayed_extent_range(inode, last, last, &es);

		if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {

			if (last != start)

				dataoff = last << blkbits;

				dataoff = (loff_t)last << blkbits;

			break;

		}
@@ -486,7 +486,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) 
		}



		last++;

		dataoff = last << blkbits;

		dataoff = (loff_t)last << blkbits;

	} while (last <= end);



	mutex_unlock(&inode->i_mutex);
@@ -540,7 +540,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) 
		ret = ext4_map_blocks(NULL, inode, &map, 0);

		if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {

			last += ret;

			holeoff = last << blkbits;

			holeoff = (loff_t)last << blkbits;

			continue;

		}
@@ -551,7 +551,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) 
		ext4_es_find_delayed_extent_range(inode, last, last, &es);

		if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {

			last = es.es_lblk + es.es_len;

			holeoff = last << blkbits;

			holeoff = (loff_t)last << blkbits;

			continue;

		}
@@ -566,7 +566,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) 
							      &map, &holeoff);

			if (!unwritten) {

				last += ret;

				holeoff = last << blkbits;

				holeoff = (loff_t)last << blkbits;

				continue;

			}

		}