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authorJan Kara <jack@suse.cz>2013-05-31 19:37:56 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-21 18:21:32 -0700
commit80747f06d94394d0c2bc384515abe0ba460e58f4 (patch)
tree4a5081790f777be5c7fcd39bc4e1652dabedb460
parente47438e6af1377ae8b29d2c0262513f54f17adcd (diff)
downloadvexpress-lsk-80747f06d94394d0c2bc384515abe0ba460e58f4.tar.gz
ext4: fix overflows in SEEK_HOLE, SEEK_DATA implementations
commit e7293fd146846e2a44d29e0477e0860c60fb856b upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/ext4/file.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1b4d51b5d8..b19f0a457f3 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -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;
}
}