Correct bitwise test in mac_bsdextended ugidfw_rule_valid()

[emaste]

Summary

https://www.viva64.com/en/b/0496/

Reported by: PVS-Studio
PR: 218039

[emaste]

For reference this is also CID 1008934.

[kib]

sys/security/mac_bsdextended/mac_bsdextended.c

128 ↗

(On Diff #27149)

Shouldn't this be mbo_flags instead of mbo_neg ?

Also, stylish test would be () != 0.

[emaste]

sys/security/mac_bsdextended/mac_bsdextended.c

128 ↗

(On Diff #27149)

For reference this was introduced in rS157986, which introduced this non-stylistic change.

Perhaps we should just remove the first condition in this if, leaving

if ((rule->mbr_object.mbo_type | MBO_ALL_TYPE) != MBO_ALL_TYPE)

I.e., disallow invalid mbo_type flags regardless of whether MBO_TYPE_DEFINED is set?

[emaste]

As suggested by @kib I think this is the intended test.

The test currently in svn is in effect if (1 && ...) so removing the first part (as in my comment) should be no functional change, but I suppose this is actually what's intended; mbo_type is only accessed if rule->mbr_object.mbo_flags & MBO_TYPE_DEFINED.

[kib]

sys/security/mac_bsdextended/mac_bsdextended.c

128 ↗

(On Diff #29165)

Still, I prefer to add != 0 .