git: 0746301c4995 - main - ssh: pass 0 to procctl(2) to operate on self
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Date: Fri, 21 Jan 2022 00:56:00 UTC
The branch main has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=0746301c4995d9e4a82b0e5034b62e310694d1ef commit 0746301c4995d9e4a82b0e5034b62e310694d1ef Author: Ed Maste <emaste@FreeBSD.org> AuthorDate: 2022-01-20 18:41:39 +0000 Commit: Ed Maste <emaste@FreeBSD.org> CommitDate: 2022-01-21 00:54:49 +0000 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 --- crypto/openssh/platform-tracing.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/crypto/openssh/platform-tracing.c b/crypto/openssh/platform-tracing.c index 740a266b9432..e00f015fb01e 100644 --- a/crypto/openssh/platform-tracing.c +++ b/crypto/openssh/platform-tracing.c @@ -41,7 +41,7 @@ platform_disable_tracing(int strict) /* On FreeBSD, we should make this process untraceable */ int disable_trace = PROC_TRACE_CTL_DISABLE; - if (procctl(P_PID, getpid(), PROC_TRACE_CTL, &disable_trace) && strict) + if (procctl(P_PID, 0, PROC_TRACE_CTL, &disable_trace) && strict) fatal("unable to make the process untraceable"); #endif #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)