K 10
svn:author
V 6
emaste
K 8
svn:date
V 27
2022-02-15T16:07:06.885242Z
K 7
svn:log
V 1068
ssh: pass 0 to procctl(2) to operate on self

As of f833ab9dd187 procctl(2) allows idtype P_PID with id = 0 as a
shortcut for the calling process ID.  The shortcut also bypasses the
p_cansee / p_candebug test (since the process is able to act on itself.)

At present if the security.bsd.unprivileged_proc_debug sysctl is 0 then
procctl(P_PID, getpid(), ... for a process to act on itself will fail,
but procctl(P_PID, 0, ... will succeed.  This should likely be addressed
with a kernel change.

In any case the id = 0 shortcut is a tiny optimization for a process to
act on itself and allows the self-procctl to succeed, so use it in ssh.

Reported by:	Shawn Webb
Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33970

(cherry picked from commit 0746301c4995d9e4a82b0e5034b62e310694d1ef)
(cherry picked from commit e38610abcadbfeba5f7a32aa8a6bc8981be64908)
(cherry picked from commit abf5f2e6932d6603c50c647a90d4e602e654003e)

Git Hash:   b5b1a6960f33d3afbfe12f7897644a52a0e5336b
Git Author: emaste@FreeBSD.org
END