[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>

2 files changed, 23 insertions, 6 deletions

diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index c19be8fc3e51..b41a7d7e20f0 100644
--- a/fs/ext3/balloc.c
+++ b/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();
                 }
diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
index e186f7fb698b..9e318a5cfc87 100644
--- a/fs/ext3/resize.c
+++ b/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;