| From | Kamal Mostafa <> | Subject | [PATCH 087/145] ext4: fix overflows in SEEK_HOLE, SEEK_DATA implementations | Date | Wed, 17 Jul 2013 15:46:59 -0700 |
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3.8.13.5 -stable review patch. If anyone has any objections, please let me know.
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From: Jan Kara <jack@suse.cz>
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> [ luis: backported to 3.8: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/ext4/file.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 405565a..216a633 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -311,7 +311,7 @@ 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; @@ -456,7 +456,7 @@ 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; } @@ -469,7 +469,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) if (last >= es.start && last < es.start + es.len) { if (last != start) - dataoff = last << blkbits; + dataoff = (loff_t)last << blkbits; break; } @@ -487,7 +487,7 @@ 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); @@ -541,7 +541,7 @@ 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; } @@ -554,7 +554,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) if (last >= es.start && last < es.start + es.len) { last = es.start + es.len; - holeoff = last << blkbits; + holeoff = (loff_t)last << blkbits; continue; } @@ -569,7 +569,7 @@ 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; } } -- 1.8.1.2
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