tree d084d80f132139ee5372bb5cf56989225000b974
parent 2b9f5be886da2bb54ff06682da2535d6df08d039
author Stéphane Lesimple <speed47_github@speed47.net> 1641808350 +0100
committer Treehugger Robot <treehugger-gerrit@google.com> 1641924389 +0000

minijail0: use gid_t/uid_t for set_group/set_user/add_suppl_group

set_group(), set_user() and add_suppl_group() all have been using
the type "int" to read uid/gid from strtod(), then implicitly
converting to uid_t/gid_t when using libminijail.

This makes an assumption about the signedness of gid_t/uid_t
of the system we're running on. Unfortunately this assumption is
more often wrong than not, as on recent systems these types tend
to map to "unsigned long".

This assumption prevents us from using any uid/gid > 2^32/2 on
recent systems. The change we're introducing is simply to use
uid_t/gid_t instead of int.

We also replace strtod() by strtoul() as we expect to only ever
parse integers instead of doubles.

- Before this patch is applied:
$ minijail0 -u $((2**32-2)) -g $((2**32-2)) --add-suppl-group $((2**32-3)) /usr/bin/id
uid=2147483648 gid=2147483648 groups=2147483648

- After this patch is applied:
$ minijail0 -u $((2**32-2)) -g $((2**32-2)) --add-suppl-group $((2**32-3)) /usr/bin/id
uid=4294967294 gid=4294967294 groups=4294967294,4294967293

This applies only to minijail0, as libminijail
already uses uid_t/gid_t properly.

Change-Id: I8b45d6f8856bbc47be6d37de7d449c38943c2bb5