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 160991d6d3126be1c887b86da7dbde64f28bedee..b9870f7388f113875bc2188a8e8f6276444da8a3 100644 (file)
--- a/e2fsck/super.c
+++ b/e2fsck/super.c
@@ -317,7 +317,8 @@ void check_resize_inode(e2fsck_t ctx)
        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 @@ int check_backup_super_block(e2fsck_t ctx)
                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 775dfcc477347a5ca0b5b9cc3cdd82388613edd8..0c829edb02688132c2ab5a934cb5a4cc86230fb9 100644 (file)
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -41,8 +41,7 @@ static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
            !(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 @@ static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
        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 4d6af883e3433d502d2e9849f5230d980624ea8d..9cc7cba2eefff6b66bfc1459ab14d50ce75d8e58 100644 (file)
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -934,8 +934,7 @@ errcode_t ext2fs_extent_node_split(ext2_extent_handle_t handle)
 
                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 c154d916844b274adc4c74f5c3c39b3092cac1df..c636a9757d7746a8ac3c8cf4cf7e1709ba88ed0a 100644 (file)
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -358,9 +358,7 @@ static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
                    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 ac965ee6934c93fe9b3cfc08769ec450c54140b0..8fdf35c2adba8884c984a5826b40baa61c3ffdea 100644 (file)
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -492,9 +492,8 @@ retry:
        /*
         * 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 @@ static errcode_t adjust_superblock(ext2_resize_t rfs, blk64_t new_size)
                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) {