[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>

1 files changed, 17 insertions, 0 deletions

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;