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: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1b4d51b5d86..b19f0a457f32 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;
                         }
                 }