Fix 32-bit overflow problems: dgrp_t * s_blocks_per_group
There are a number of places where we multiply a dgrp_t with
s_blocks_per_group expecting that we will get a blk64_t. This
requires a cast, or using the convenience function
ext2fs_group_first_block2().
This audit was suggested by Eric Sandeen.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
diff --git a/e2fsck/super.c b/e2fsck/super.c
index 160991d..b9870f7 100644
--- a/e2fsck/super.c
+++ b/e2fsck/super.c
@@ -317,7 +317,8 @@
struct problem_context pctx;
int i, gdt_off, ind_off;
dgrp_t j;
- blk64_t blk, pblk, expect;
+ blk64_t blk, pblk;
+ blk_t expect; /* for resize inode, which is 32-bit only */
__u32 *dind_buf = 0, *ind_buf;
errcode_t retval;
@@ -914,8 +915,7 @@
if (!ext2fs_bg_has_super(fs, g))
continue;
- sb = fs->super->s_first_data_block +
- (g * fs->super->s_blocks_per_group);
+ sb = ext2fs_group_first_block2(fs, g);
retval = io_channel_read_blk(fs->io, sb, -SUPERBLOCK_SIZE,
buf);
diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 775dfcc..0c829ed 100644
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -41,8 +41,7 @@
!(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
return;
- blk = (group * fs->super->s_blocks_per_group) +
- fs->super->s_first_data_block;
+ blk = ext2fs_group_first_block2(fs, group);
ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
&old_desc_blk, &new_desc_blk, 0);
@@ -56,8 +55,7 @@
for (i=0; i < fs->super->s_blocks_per_group; i++, blk++)
ext2fs_fast_unmark_block_bitmap2(map, blk);
- blk = (group * fs->super->s_blocks_per_group) +
- fs->super->s_first_data_block;
+ blk = ext2fs_group_first_block2(fs, group);
for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
if ((blk == super_blk) ||
(old_desc_blk && old_desc_blocks &&
diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index 4d6af88..9cc7cba 100644
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -934,8 +934,7 @@
if (log_flex)
group = group & ~((1 << (log_flex)) - 1);
- goal_blk = (group * handle->fs->super->s_blocks_per_group) +
- handle->fs->super->s_first_data_block;
+ goal_blk = ext2fs_group_first_block2(handle->fs, group);
}
retval = ext2fs_alloc_block2(handle->fs, goal_blk, block_buf,
&new_node_pblk);
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index c154d91..c636a97 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -358,9 +358,7 @@
ext2fs_bg_free_blocks_count(fs, group))
group = i;
- es.goal = (fs->super->s_blocks_per_group * group) +
- fs->super->s_first_data_block;
-
+ es.goal = ext2fs_group_first_block2(fs, group);
retval = ext2fs_block_iterate3(fs, journal_ino, BLOCK_FLAG_APPEND,
0, mkjournal_proc, &es);
if (es.err) {
diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index ac965ee..8fdf35c 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -492,9 +492,8 @@
/*
* Initialize the new block group descriptors
*/
- group_block = fs->super->s_first_data_block +
- old_fs->group_desc_count * fs->super->s_blocks_per_group;
-
+ group_block = ext2fs_group_first_block2(fs,
+ old_fs->group_desc_count);
csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
if (access("/sys/fs/ext4/features/lazy_itable_init", F_OK) == 0)
@@ -651,9 +650,8 @@
goto errout;
memset(rfs->itable_buf, 0, fs->blocksize * fs->inode_blocks_per_group);
- group_block = fs->super->s_first_data_block +
- rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group;
-
+ group_block = ext2fs_group_first_block2(fs,
+ rfs->old_fs->group_desc_count);
adj = rfs->old_fs->group_desc_count;
max_group = fs->group_desc_count - adj;
if (rfs->progress) {