fs/ext4: fix calling put_ext4 with truncated offset
Curently, we are using 32 bit multiplication to calculate the offset,
so the result will always be 32 bit.
This can silently cause file system corruption when performing a write
operation on partition larger than 4 GiB.
This patch address the issue by simply promoting the terms to 64 bit,
and let compilers decide how to do the multiplication efficiently.
Signed-off-by: Ma Haijun <mahaijuns@gmail.com>
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index 1e1924c..b674b6f 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -40,18 +40,18 @@
/* update block groups */
for (i = 0; i < fs->no_blkgrp; i++) {
fs->bgd[i].bg_checksum = ext4fs_checksum_update(i);
- put_ext4((uint64_t)(fs->bgd[i].block_id * fs->blksz),
+ put_ext4((uint64_t)((uint64_t)fs->bgd[i].block_id * (uint64_t)fs->blksz),
fs->blk_bmaps[i], fs->blksz);
}
/* update inode table groups */
for (i = 0; i < fs->no_blkgrp; i++) {
- put_ext4((uint64_t) (fs->bgd[i].inode_id * fs->blksz),
+ put_ext4((uint64_t) ((uint64_t)fs->bgd[i].inode_id * (uint64_t)fs->blksz),
fs->inode_bmaps[i], fs->blksz);
}
/* update the block group descriptor table */
- put_ext4((uint64_t)(fs->gdtable_blkno * fs->blksz),
+ put_ext4((uint64_t)((uint64_t)fs->gdtable_blkno * (uint64_t)fs->blksz),
(struct ext2_block_group *)fs->gdtable,
(fs->blksz * fs->no_blk_pergdt));
@@ -709,7 +709,7 @@
temp_buff);
jsb = (struct journal_superblock_t *)temp_buff;
jsb->s_start = cpu_to_be32(0);
- put_ext4((uint64_t) (blknr * fs->blksz),
+ put_ext4((uint64_t) ((uint64_t)blknr * (uint64_t)fs->blksz),
(struct journal_superblock_t *)temp_buff, fs->blksz);
free(temp_buff);
}
@@ -793,7 +793,7 @@
delayed_next += blockend >> log2blksz;
} else { /* spill */
put_ext4((uint64_t)
- (delayed_start << log2blksz),
+ ((uint64_t)delayed_start << log2blksz),
delayed_buf,
(uint32_t) delayed_extent);
previous_block_number = blknr;
@@ -814,7 +814,7 @@
} else {
if (previous_block_number != -1) {
/* spill */
- put_ext4((uint64_t) (delayed_start <<
+ put_ext4((uint64_t) ((uint64_t)delayed_start <<
log2blksz),
delayed_buf,
(uint32_t) delayed_extent);
@@ -826,7 +826,7 @@
}
if (previous_block_number != -1) {
/* spill */
- put_ext4((uint64_t) (delayed_start << log2blksz),
+ put_ext4((uint64_t) ((uint64_t)delayed_start << log2blksz),
delayed_buf, (uint32_t) delayed_extent);
previous_block_number = -1;
}