From: Juergen Perlinger <perlinger@ntp.org>
Date: Mon, 18 Nov 2019 06:04:58 +0000 (+0000)
Subject: [Bug 3627] SIGSEGV on FreeBSD-12 with stack limit and stack gap
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a3cd67fa8d862cfc1161fd36fa2e92324f04287f;p=thirdparty%2Fntp.git

[Bug 3627] SIGSEGV on FreeBSD-12 with stack limit and stack gap

bk: 5dd2348a1iVN4sHfn4J1yan-8Mre_Q
---

diff --git a/ChangeLog b/ChangeLog
index 56a2d6023..573dd533f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,8 @@
 
 * [Sec 3610] process_control() should bail earlier on short packets. stenn@
   - Reported by Philippe Antoine
+* [Bug 3627] SIGSEGV on FreeBSD-12 with stack limit and stack gap <perlinger@ntp.org>
+  - integrated patch by Cy Schubert
 * [Bug 3620] memory leak in ntpq sysinfo <perlinger@ntp.org>
   - applied patch by Gerry Garvey
 * [Bug 3619] Honour drefid setting in cooked mode and sysinfo <perlinger@ntp.org>
diff --git a/ntpd/ntpd.c b/ntpd/ntpd.c
index 86c608fbd..7e050faad 100644
--- a/ntpd/ntpd.c
+++ b/ntpd/ntpd.c
@@ -145,6 +145,17 @@
 # include <seccomp.h>
 #endif /* LIBSECCOMP and KERN_SECCOMP */
 
+#ifdef __FreeBSD__
+#include <sys/procctl.h>
+#ifndef PROC_STACKGAP_CTL
+/*
+ * Even if we compile on an older system we can still run on a newer one.
+ */
+#define	PROC_STACKGAP_CTL	17
+#define	PROC_STACKGAP_DISABLE	0x0002
+#endif
+#endif
+
 #ifdef HAVE_DNSREGISTRATION
 # include <dns_sd.h>
 DNSServiceRef mdns;
@@ -427,6 +438,18 @@ main(
 	char *argv[]
 	)
 {
+#   ifdef __FreeBSD__
+	{
+		/*
+		 * We Must disable ASLR stack gap on FreeBSD to avoid a
+		 * segfault. See PR/241421 and PR/241960.
+		 */
+		int aslr_var = PROC_STACKGAP_DISABLE;
+
+		pid_t my_pid = getpid();
+		procctl(P_PID, my_pid, PROC_STACKGAP_CTL, &aslr_var); 
+	}
+#   endif
 	return ntpdmain(argc, argv);
 }
 #endif /* !SYS_WINNT */