Bug report - segfault sshd

John Fawcett john at voipsupport.it
Fri Dec 23 23:10:42 AEDT 2016

When logging in via ssh with user root and password authentication I get
a segfault in sshd. The problem is 100% reproduceable - I cannot login
remotely at all. Any help appreciated in trying to get this addressed.

This is a centos 7.3 with all the latest updates applied


Here's a backtrace captured by running sshd under gdb.

/usr/sbin/sshd -d
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
process 14806 is executing new program: /usr/sbin/sshd
Missing separate debuginfos, use: debuginfo-install
nss-softokn-freebl- pcre-8.32-15.el7_2.1.x86_64
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Detaching after fork from child process 14810.

Program received signal SIGSEGV, Segmentation fault.
__strcmp_ssse3 () at ../sysdeps/x86_64/strcmp.S:212
212        movlpd    (%rdi), %xmm1
Missing separate debuginfos, use: debuginfo-install
bzip2-libs-1.0.6-13.el7.x86_64 cracklib-2.9.0-11.el7.x86_64
elfutils-libelf-0.166-2.el7.x86_64 elfutils-libs-0.166-2.el7.x86_64
keyutils-libs-1.5.8-3.el7.x86_64 libattr-2.4.46-12.el7.x86_64
libcap-2.22-8.el7.x86_64 libgcc-4.8.5-11.el7.x86_64
nss-softokn-freebl- pcre-8.32-15.el7_2.1.x86_64
systemd-libs-219-30.el7_3.6.x86_64 xz-libs-5.2.2-1.el7.x86_64
#0  __strcmp_ssse3 () at ../sysdeps/x86_64/strcmp.S:212
#1  0x0000555555584f2f in sshpam_auth_passwd
(authctxt=authctxt at entry=0x55555581fdb0,
password=password at entry=0x555555839900 "************") at auth-pam.c:1207
#2  0x000055555556446b in auth_password (authctxt=0x55555581fdb0,
password=password at entry=0x555555839900 "************") at auth-passwd.c:149
#3  0x0000555555578daa in mm_answer_authpassword (sock=5,
m=0x7fffffffda10) at monitor.c:860
#4  0x000055555557b9b1 in monitor_read
(pmonitor=pmonitor at entry=0x55555581efb0, ent=0x55555580a390
<mon_dispatch_proto20+80>, pent=pent at entry=0x7fffffffda78) at monitor.c:586
#5  0x000055555557c7bc in monitor_child_preauth
(_authctxt=_authctxt at entry=0x55555581fdb0, pmonitor=0x55555581efb0) at
#6  0x00005555555615f5 in privsep_preauth (authctxt=0x55555581fdb0) at
#7  main (ac=<optimized out>, av=<optimized out>) at sshd.c:2094

More information about the openssh-unix-dev mailing list