From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C205C43381 for ; Fri, 1 Mar 2019 12:31:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66E3920850 for ; Fri, 1 Mar 2019 12:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727052AbfCAMbi convert rfc822-to-8bit (ORCPT ); Fri, 1 Mar 2019 07:31:38 -0500 Received: from mail.lysator.liu.se ([130.236.254.3]:49927 "EHLO mail.lysator.liu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbfCAMbi (ORCPT ); Fri, 1 Mar 2019 07:31:38 -0500 X-Greylist: delayed 354 seconds by postgrey-1.27 at vger.kernel.org; Fri, 01 Mar 2019 07:31:37 EST Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id E92B040006 for ; Fri, 1 Mar 2019 13:25:42 +0100 (CET) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id CEB3840013; Fri, 1 Mar 2019 13:25:42 +0100 (CET) Received: from [IPv6:2001:6b0:17:f002:4c86:fa6d:33dc:a323] (unknown [IPv6:2001:6b0:17:f002:4c86:fa6d:33dc:a323]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id 2AFDE40006 for ; Fri, 1 Mar 2019 13:25:42 +0100 (CET) From: Peter Eriksson Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: [Bug report] NULL-pointer dereference in gssd (nfs-utils version 1.3.4 & 2.3.3) Message-Id: <77C72E28-D137-408E-834B-623341F21BB3@lysator.liu.se> Date: Fri, 1 Mar 2019 13:25:40 +0100 To: linux-nfs@vger.kernel.org X-Mailer: Apple Mail (2.3445.102.3) X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org I’m seeing Segmentation Faults in gssd from nfs-utils 1.3.4 and 2.3.3 when running it on a machine running CentOS 7.6.1810 / kernel 3.10.0-957.5.1.el7.x86_64 that uses GSSAPI quite a bit (a Linux machine doing validation checks of our fileserver - runs a list of SMB/NFS/LDAP/Kerberos check every minute 24/7). We compiled our own version since the version that CentOS delivers (1.3.0) also crashed (unsure if it is the same bug there though). # gdb ./gssd (gdb) run -f -v ... [New Thread 0x7fffef7fe700 (LWP 24902)] Error doing scandir on directory '/run/user/11189': No such file or directory [Thread 0x7fffef7fe700 (LWP 24902) exited] [New Thread 0x7fffeffff700 (LWP 24904)] Error doing scandir on directory '/run/user/11189': No such file or directory [Thread 0x7fffeffff700 (LWP 24904) exited] Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7ffff4cec700 (LWP 24448)] create_auth_rpc_client (clp=clp@entry=0x621590, tgtname=tgtname@entry=0x0, clnt_return=clnt_return@entry=0x7ffff4cebd48, auth_return=auth_return@entry=0x7ffff4cebcd0, uid=uid@entry=0, authtype=authtype@entry=0, cred=cred@entry=0x0) at gssd_proc.c:352 352 if ((strcmp(clp->protocol, "udp")) == 0) Missing separate debuginfos, use: debuginfo-install glibc-2.17-260.el7_6.3.x86_64 gssproxy-0.7.0-21.el7.x86_64 keyutils-libs-1.5.8-3.el7.x86_64 krb5-libs-1.15.1-37.el7_6.x86_64 libcom_err-1.42.9-13.el7.x86_64 libevent-2.0.21-4.el7.x86_64 libselinux-2.5-14.1.el7.x86_64 libtirpc-0.2.4-0.15.el7.x86_64 pcre-8.32-17.el7.x86_64 (gdb) where #0 create_auth_rpc_client (clp=clp@entry=0x621590, tgtname=tgtname@entry=0x0, clnt_return=clnt_return@entry=0x7ffff4cebd48, auth_return=auth_return@entry=0x7ffff4cebcd0, uid=uid@entry=0, authtype=authtype@entry=0, cred=cred@entry=0x0) at gssd_proc.c:352 #1 0x0000000000406d21 in krb5_use_machine_creds (rpc_clnt=0x7ffff4cebd48, service=0x6293c0 "*", tgtname=0x0, srchost=0x0, uid=0, clp=0x621590) at gssd_proc.c:569 #2 process_krb5_upcall (clp=clp@entry=0x621590, uid=uid@entry=0, fd=13, srchost=srchost@entry=0x0, tgtname=tgtname@entry=0x0, service=service@entry=0x6293c0 "*") at gssd_proc.c:657 #3 0x000000000040759c in handle_gssd_upcall (info=0x6293a0) at gssd_proc.c:819 #4 0x00007ffff6de6dd5 in start_thread () from /lib64/libpthread.so.0 #5 0x00007ffff68f6ead in clone () from /lib64/libc.so.6 (gdb) frame 0 #0 create_auth_rpc_client (clp=clp@entry=0x621590, tgtname=tgtname@entry=0x0, clnt_return=clnt_return@entry=0x7ffff4cebd48, auth_return=auth_return@entry=0x7ffff4cebcd0, uid=uid@entry=0, authtype=authtype@entry=0, cred=cred@entry=0x0) at gssd_proc.c:352 352 if ((strcmp(clp->protocol, "udp")) == 0) (gdb) list 347 348 printerr(2, "creating %s client for server %s\n", clp->protocol, 349 clp->servername); 350 351 protocol = IPPROTO_TCP; 352 if ((strcmp(clp->protocol, "udp")) == 0) 353 protocol = IPPROTO_UDP; 354 355 switch (addr->sa_family) { 356 case AF_INET: (gdb) print clp $1 = (struct clnt_info *) 0x621590 (gdb) print clp->protocol $2 = 0x0 (gdb) print *clp $3 = {list = {tqe_next = 0x0, tqe_prev = 0xffffffff}, wd = 0, scanned = false, name = 0x0, relpath = 0x0, servicename = 0x0, servername = 0x0, prog = 0, vers = 0, protocol = 0x0, krb5_fd = 0, krb5_ev = {ev_active_next = { tqe_next = 0x0, tqe_prev = 0x0}, ev_next = {tqe_next = 0x0, tqe_prev = 0x0}, ev_timeout_pos = {ev_next_with_common_timeout = { tqe_next = 0x0, tqe_prev = 0x0}, min_heap_idx = 0}, ev_fd = 0, ev_base = 0x0, _ev = {ev_io = {ev_io_next = {tqe_next = 0x0, tqe_prev = 0x0}, ev_timeout = {tv_sec = 0, tv_usec = 0}}, ev_signal = {ev_signal_next = {tqe_next = 0x0, tqe_prev = 0x0}, ev_ncalls = 0, ev_pncalls = 0x0}}, ev_events = 0, ev_res = 0, ev_flags = 0, ev_pri = 0 '\000', ev_closure = 0 '\000', ev_timeout = { tv_sec = 0, tv_usec = 0}, ev_callback = 0x0, ev_arg = 0x0}, gssd_fd = 0, gssd_ev = {ev_active_next = {tqe_next = 0x0, tqe_prev = 0x0}, ev_next = { tqe_next = 0x0, tqe_prev = 0x0}, ev_timeout_pos = { ev_next_with_common_timeout = {tqe_next = 0x0, tqe_prev = 0x0}, min_heap_idx = 0}, ev_fd = 496, ev_base = 0x70, _ev = {ev_io = { ev_io_next = {tqe_next = 0x0, tqe_prev = 0x7f3865333232}, ev_timeout = {tv_sec = 0, tv_usec = 273}}, ev_signal = { ev_signal_next = {tqe_next = 0x0, tqe_prev = 0x7f3865333232}, ev_ncalls = 0, ev_pncalls = 0x111}}, ev_events = -1864, ev_res = -2373, ev_flags = 32767, ev_pri = 0 '\000', ev_closure = 0 '\000', ev_timeout = {tv_sec = 140737332902072, tv_usec = 4294977170}, ev_callback = 0x6218c4, ev_arg = 0x240}, addr = { ---Type to continue, or q to quit--- ss_family = 32, __ss_padding = "\000\000\000\000\000\000\260\020b\000\000\000\000\000\270\367\273\366\377\177\000\000`\002\000\000\000\000\000\000\301\000\000\000\000\000\000\000\360\027b\000\000\000\000\000\000\214b", '\000' , "\241\000\000\000\000\000\000\000\200\021b\000\000\000\000\000H\370\273\366\377\177", '\000' , "q\000\000\000\000\000\000", __ss_align = 6427008}} (gdb) frame 1 #1 0x0000000000406d21 in krb5_use_machine_creds (rpc_clnt=0x7ffff4cebd48, service=0x6293c0 "*", tgtname=0x0, srchost=0x0, uid=0, clp=0x621590) at gssd_proc.c:569 569 if ((create_auth_rpc_client(clp, tgtname, rpc_clnt, (gdb) list 564 printerr(1, "WARNING: gss_krb5_ccache_name " 565 "with name '%s' failed (%s)\n", 566 *ccname, error_message(min_stat)); 567 continue; 568 } 569 if ((create_auth_rpc_client(clp, tgtname, rpc_clnt, 570 &auth, uid, 571 AUTHTYPE_KRB5, 572 GSS_C_NO_CREDENTIAL)) == 0) { 573 /* Success! */ (gdb) print tgtname $6 = 0x0 (gdb) print rpc_clnt $7 = (CLIENT **) 0x7ffff4cebd48 (gdb) print *rpc_clnt $8 = (CLIENT *) 0x0 (gdb) frame 2 #2 process_krb5_upcall (clp=clp@entry=0x621590, uid=uid@entry=0, fd=13, srchost=srchost@entry=0x0, tgtname=tgtname@entry=0x0, service=service@entry=0x6293c0 "*") at gssd_proc.c:657 657 auth = krb5_use_machine_creds(clp, uid, srchost, tgtname, (gdb) list 652 goto out_return_error; 653 } 654 if (auth == NULL) { 655 if (uid == 0 && (root_uses_machine_creds == 1 || 656 service != NULL)) { 657 auth = krb5_use_machine_creds(clp, uid, srchost, tgtname, 658 service, &rpc_clnt); 659 if (auth == NULL) 660 goto out_return_error; 661 } else { (gdb) print uid $9 = 0 (gdb) print srchost $10 = 0x0 (gdb) print tgtname $11 = 0x0 Exactly what is causing this event to happen is unclear (a lot of automated checks are running, but they run well for a couple of hours before this crash occur). Please let me know if there is some other information someone might need to fix this bug… (I’m going to add sanity checks to the code in order to try to mitigate the crash and instead fail in a more “nice” way). - Peter