[PATCH] more ext3 16T overflow fixes

Some of the changes in balloc.c are just cosmetic, as Andreas pointed out -
if they overflow they'll then underflow and things are fine.

5th hunk actually fixes an overflow problem.

Also check for potential overflows in inode & block counts when resizing.

Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Cc: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ext3/balloc.c

@@ -202,7 +202,7 @@ goal_in_my_reservation(struct ext3_reserve_window *rsv, ext3_grpblk_t grp_goal,
 	ext3_fsblk_t group_first_block, group_last_block;
 
 	group_first_block = ext3_group_first_block_no(sb, group);
-	group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+	group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	if ((rsv->_rsv_start > group_last_block) ||
 	    (rsv->_rsv_end < group_first_block))
@@ -1047,7 +1047,7 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
 	spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
 
 	group_first_block = ext3_group_first_block_no(sb, group);
-	group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+	group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	if (grp_goal < 0)
 		start_block = group_first_block;
@@ -1239,7 +1239,7 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
 			struct ext3_reserve_window_node * my_rsv,
 			unsigned long *count, int *errp)
 {
-	ext3_fsblk_t group_first_block;
+	ext3_fsblk_t group_first_block, group_last_block;
 	ext3_grpblk_t ret = 0;
 	int fatal;
 	unsigned long num = *count;
@@ -1276,6 +1276,7 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
 	 * first block is the block number of the first block in this group
 	 */
 	group_first_block = ext3_group_first_block_no(sb, group);
+	group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	/*
 	 * Basically we will allocate a new block from inode's reservation
@@ -1311,9 +1312,8 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
 			try_to_extend_reservation(my_rsv, sb,
 					*count-my_rsv->rsv_end + grp_goal - 1);
 
-		if ((my_rsv->rsv_start >= group_first_block +
-					EXT3_BLOCKS_PER_GROUP(sb))
-		    || (my_rsv->rsv_end < group_first_block)) {
+		if ((my_rsv->rsv_start > group_last_block) ||
+				(my_rsv->rsv_end < group_first_block)) {
 			rsv_window_dump(&EXT3_SB(sb)->s_rsv_window_root, 1);
 			BUG();
 		}

fs/ext3/resize.c

@@ -731,6 +731,18 @@ int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
 		return -EPERM;
 	}
 
+	if (le32_to_cpu(es->s_blocks_count) + input->blocks_count <
+	    le32_to_cpu(es->s_blocks_count)) {
+		ext3_warning(sb, __FUNCTION__, "blocks_count overflow\n");
+		return -EINVAL;
+	}
+
+	if (le32_to_cpu(es->s_inodes_count) + EXT3_INODES_PER_GROUP(sb) <
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext3_warning(sb, __FUNCTION__, "inodes_count overflow\n");
+		return -EINVAL;
+	}
+
 	if (reserved_gdb || gdb_off == 0) {
 		if (!EXT3_HAS_COMPAT_FEATURE(sb,
 					     EXT3_FEATURE_COMPAT_RESIZE_INODE)){
@@ -959,6 +971,11 @@ int ext3_group_extend(struct super_block *sb, struct ext3_super_block *es,
 
 	add = EXT3_BLOCKS_PER_GROUP(sb) - last;
 
+	if (o_blocks_count + add < o_blocks_count) {
+		ext3_warning(sb, __FUNCTION__, "blocks_count overflow");
+		return -EINVAL;
+	}
+
 	if (o_blocks_count + add > n_blocks_count)
 		add = n_blocks_count - o_blocks_count;