ext4: add check for inodes_count overflow in new resize ioctl
Addresses-Red-Hat-Bugzilla: #913245
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Cc: stable@vger.kernel.org
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 08d2312..b27c96d 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1882,6 +1882,10 @@
return 0;
n_group = ext4_get_group_number(sb, n_blocks_count - 1);
+ if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
+ ext4_warning(sb, "resize would cause inodes_count overflow");
+ return -EINVAL;
+ }
ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
n_desc_blocks = num_desc_blocks(sb, n_group + 1);