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ext4: fix overflows in SEEK_HOLE, SEEK_DATA implementations

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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: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
This commit is contained in:
Jan Kara 2013-05-31 19:37:56 -04:00 committed by Theodore Ts'o
parent eaf3793728
commit e7293fd146
1 changed files with 7 additions and 7 deletions
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14
fs/ext4/file.c
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@ -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;
}
}