storing a value larger than UINT_MAX

Hello ext4 developers,

I am trying to run a kernel with grsecurity with the size overflow
protection and am getting the following warnings / errors:

dmesg: http://pastebin.com/wr3UGLS9
config: http://pastebin.com/sr8M9bP0
mballoc.* (make fs/ext4/mballoc.o EXTRA_CFLAGS="-fdump-tree-all
-fdump-ipa-all") http://filebin.ca/3DMIChVw9lQM/mballoc.tgz

According to the grsecurity developers it seems to be a bug in ext4:
https://forums.grsecurity.net/viewtopic.php?f=1&t=4678&p=16971

The response from ephox (PAX team / grsecurity developer):
--
Thanks for the report. I think this is an upstream bug. Based on the
runtime values provided by you, ext4_mb_new_group_pa() tries to store a
value into pa->pa_lstart which larger than UINT_MAX which comes from
ext4_group_first_block_no().
Could you please report it to the ext4 developers?
--

I'll try to answer all the questions but I'm not an expert in this area.

I am also not subscribed to this mailinglist so please keep me in the CC.

Regards,

Matthijs Möhlmann