Date: Thu, 1 Feb 2007 11:09:00 GMT From: Ludovic FLAMENT<ludovic.flament@netasq.com> To: freebsd-gnats-submit@FreeBSD.org Subject: bin/108656: Segfault of sshd for unknown user when privilege separation is off and PAM is used Message-ID: <200702011109.l11B90lK023743@www.freebsd.org> Resent-Message-ID: <200702011110.l11BAVul083537@freefall.freebsd.org>
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>Number: 108656 >Category: bin >Synopsis: Segfault of sshd for unknown user when privilege separation is off and PAM is used >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Feb 01 11:10:31 GMT 2007 >Closed-Date: >Last-Modified: >Originator: Ludovic FLAMENT >Release: 6.2-RELEASE >Organization: NETASQ >Environment: FreeBSD build 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Wed Jan 17 11:24:47 CET 2007 ludovicf@build:/usr/obj/usr/src/sys/SMP i386 >Description: When we not used separation privilege, and we do a connection with a username that aren't known, sshd segfault We use PAM, but I don't think that problem is linked on, because when we see my solution to fix this crash, PAM have no impact. pid 2029 (sshd), uid 0: exited on signal 11 (core dumped) >How-To-Repeat: Put this option on sshd_config file ChallengeResponseAuthentication yes PasswordAuthentication no PermitEmptyPasswords no PermitRootLogin yes UsePrivilegeSeparation no connect on sshd with an unknwon username >Fix: in file /usr/src/crypto/openssh/auth.c in function fakepw(void) replace the 2 lines : fake.pw_uid = privsep_pw->pw_uid; fake.pw_gid = privsep_pw->pw_gid; by : if (use_privsep && (privsep_pw != NULL)) { fake.pw_uid = privsep_pw->pw_uid; fake.pw_gid = privsep_pw->pw_gid; } else { fake.pw_uid = (uid_t)-1; fake.pw_gid = (gid_t)-1; } >Release-Note: >Audit-Trail: >Unformatted:
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