Follow FreeBSD 11.4 sys_setresuid and sys_setresgid (sys/kern/kern_prot.c):
accept real, effective, and saved user and group IDs for the guest process,
which is assumed to run as root with IDs 0. Setting an ID to 0 or -1 (unchanged)
is accepted without changing credentials and returns 0; any other value throws.
Cover both in guest_credentials test and update libkernel debt documentation.
Follow FreeBSD 11.4 sys_getresuid and sys_getresgid (sys/kern/kern_prot.c):
retrieve real, effective, and saved user and group IDs for the guest process,
which is assumed to run as root with IDs 0. Pointers that are not null receive 0,
null pointers are ignored, and 0 is returned leaving errno unchanged on success.
Cover both in guest_credentials test and update libkernel debt documentation.
Follow FreeBSD sys_setregid and root identity model: accept real and effective group id 0 or -1 (unchanged) and change nothing; any other id throws. Update GuestCredentials test and TechnicalDebt.
`setuid`, `setreuid` and `setgroups` are absent imports of XPSemu
(PPSA97358) and PS5MC (PPSA99420) on `main`. The guest process is modelled
as root with ids 0, as `seteuid` and `setegid` already assume: `setuid`
accepts 0 and `setreuid` 0 or -1 per id and change nothing, any other id
throws. `setgroups` keeps the supplementary group list as FreeBSD's
`kern_setgroups` does (`NGROUPS_MAX` 1023, an empty list leaves the
effective group as the only entry, a first entry other than 0 throws) and
the new `getgroups` reports it. `guest_credentials` covers the accepted
ids, the default list, a set list, an empty list and the EINVAL/EFAULT
cases.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
(cherry picked from commit d12b062074dcf64bff694800d77f7261adf6f59e)
The guest process is assumed to run as root. Under FreeBSD's
sys_seteuid and sys_setegid, id 0 is then accepted without a privilege
check and changes no credential, so both return 0. Any other id would
change the effective credential, which is not modelled, and throws.
Part of #1578.
boykopovar