Date: Tue, 22 Oct 2019 20:39:36 +0000 From: bugzilla-noreply@freebsd.org To: ports-bugs@FreeBSD.org Subject: [Bug 241421] net/ntp segfaults with stack_gap!=0 Message-ID: <bug-241421-7788@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D241421 Bug ID: 241421 Summary: net/ntp segfaults with stack_gap!=3D0 Product: Ports & Packages Version: Latest Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: Individual Port(s) Assignee: cy@FreeBSD.org Reporter: dewayne@heuristicsystems.com.au Assignee: cy@FreeBSD.org Flags: maintainer-feedback?(cy@FreeBSD.org) While trying to secure... time (net/ntp), I've noticed that it experiences segmentation faults (SIGSGV). Environment FreeBSD 12.1-STABLE #0 r353429M: Sat Oct 12 19:02:59 AEDT 2019 kern.elf64.aslr.stack_gap=3D1 kern.elf64.aslr.honor_sbrk=3D1 kern.elf64.aslr.pie_enable=3D1 kern.elf64.aslr.enable=3D1 kern.elf64.pie_base=3D16912384 kern.elf64.nxstack=3D1 security.mac.ntpd.uid=3D123 security.mac.ntpd.enabled=3D1 >From the /etc/make.conf CFLAGS include -fPIE -fPIC -Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack LDFLAGS include -pie -z relro -z now -z noexecstack=20 # make -C /usr/ports/net/ntp -DUSE_K8 showconfig|grep =3Don IPV6=3Don: IPv6 protocol support LOCAL_CLOCK=3Don: Enable local clock reference SHM=3Don: Enable SHM clock attached thru shared memory SSL=3Don: SSL protocol support THREADS=3Don: Threading support And we kick-off ntp with su -m ntpd -c "/usr/local/sbin/ntpd -c /etc/ntp.conf -u ntpd -x -G --nofork" Yes this does require other files to be ntpd readable, and logs writeable With the nofork, it requires multiple tries to get it to start. Over appro= x 15 tests, the minimum number of attempts (using stack_gap=3D1) is 11 and the m= ost 41. I use a process monitor (s6) which retries starting ntp approx 1.01 seconds until successful. When kern.elf64.aslr.stack_gap=3D0, ntp starts on the first attempt. I'm sharing this because ntpd has a problem with aslr (particularly when enabled via stack_gap, and I had used different percentages stack_gap=3D1|2= |3 during additional tests). --=20 You are receiving this mail because: You are the assignee for the bug.=
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