Don't indirect user pointers directly in two 802.11s ioctls.

[jhb]

Summary

IEEE80211_MESH_RTCMD_ADD was invoking memcmp() to validate the
supplied address directly on the user pointer rather than first doing
a copyin() and validating the copied value.

IEEE80211_MESH_RTCMD_DELETE was passing the user pointer directly to
ieee80211_mesh_rt_del() rather than copying the user buffer into a
temporary kernel buffer.

Test Plan

• found in CheriBSD where user pointers and kernel pointers are different types currently
• compile tested only, no run-time testing

[brooks]

sigh

[kib]

These should have been reported by SMAP, but apparently nobody uses mesh ?

sys/net80211/ieee80211_mesh.c

3580

error != 0

[jhb]

In D24562#540481, @kib wrote:

These should have been reported by SMAP, but apparently nobody uses mesh ?

I suspect that no one uses it, yes.