Your message dated Thu, 19 Dec 2024 18:02:07 +0000 with message-id <[email protected]> and subject line Bug#1090005: Removed package(s) from unstable has caused the Debian Bug report #548894, regarding Strange segfaults at exit, suspected: gcc optimisation. to be marked as done.
This means that you claim that the problem has been dealt with. If this is not the case it is now your responsibility to reopen the Bug report if necessary, and/or fix the problem forthwith. (NB: If you are a system administrator and have no idea what this message is talking about, this may indicate a serious mail system misconfiguration somewhere. Please contact [email protected] immediately.) -- 548894: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=548894 Debian Bug Tracking System Contact [email protected] with problems
--- Begin Message ---Package: vtun Version: 3.0.2-1.1 Severity: important Hello, Disclaimer 1: this bug appears both in 3.0.2-1.1 available in lenny and in 3.0.2-2 compiled on my own using lenny toolchain/chroot - I only made one change - I've commented dh_strip from debian/rules to be able to run gdb. Disclaimer 2: I am Cc-ing gcc maintainers because I suspect this could be the main reason of this bug. Please reassing the bug to gcc package if appropriate. I noticed that vtund is segfaulting at exit on both client and server side. Results of debugging the client side are strange. First: tail of gdb output from original 3.0.2-1.1 package after using kill PID: Program received signal SIGTERM, Terminated. 0xb7f07424 in __kernel_vsyscall () (gdb) c Continuing. vtund[21632]: Closing connection Program received signal SIGSEGV, Segmentation fault. 0xb7c811bb in strlen () from /lib/i686/cmov/libc.so.6 (gdb) bt #0 0xb7c811bb in strlen () from /lib/i686/cmov/libc.so.6 #1 0xb7c4d648 in vfprintf () from /lib/i686/cmov/libc.so.6 #2 0xb7c6bcdc in vsprintf () from /lib/i686/cmov/libc.so.6 #3 0x0804e714 in ?? () #4 0xbff23185 in ?? () #5 0x08055e07 in ?? () #6 0xbff23294 in ?? () #7 0x00000000 in ?? () Now: gdb output from 3.0.2-2 (with debug symbols): Program received signal SIGTERM, Terminated. 0xb7f72424 in __kernel_vsyscall () (gdb) c Continuing. vtund[23222]: Closing connection Program received signal SIGSEGV, Segmentation fault. 0xb7cec1bb in strlen () from /lib/i686/cmov/libc.so.6 (gdb) bt #0 0xb7cec1bb in strlen () from /lib/i686/cmov/libc.so.6 #1 0xb7cb8648 in vfprintf () from /lib/i686/cmov/libc.so.6 #2 0xb7cd6cdc in vsprintf () from /lib/i686/cmov/libc.so.6 #3 0x0804e714 in set_title (fmt=0x8055e07 "%s running down commands") at lib.c:102 #4 0x0804f62d in tunnel (host=0x9f85300) at tunnel.c:225 #5 0x0804df2a in client (host=0x9f853f8) at client.c:141 #6 0x0804a917 in main (argc=4, argv=0xbfd8e384, env=0xbfd8e398) at main.c:218 Look at value of host parameter in frames 4 and 5. Let's look at line 223 of tunnel.c file: opt = linkfd(host); Just before this line host has vaule 0x9f853f8 - it's correct. Just after return from linkfd function there is 0x9f85300. Segfault comes from piece of code running from next line: set_title("%s running down commands", host->host); Because host points to invalid fragment of memory and then reference to host->host causes segfault. But there is more. File linkfd.c, line 350. Just at the beginning of linkfd function host has still value 0x9f853f8. End of this function is: setpriority(PRIO_PROCESS,0,old_prio); return linker_term; } between setpriority and return lines host still has value 0x9f853f8. And suddenly, after returning to tunnel function host is 0x9f85300. Why I suspect it could be gcc problem? First I applied followinf patch to the sources: --- vtun-3.0.2.orig/linkfd.c +++ vtun-3.0.2/linkfd.c @@ -353,6 +353,7 @@ int old_prio; lfd_host = host; + vtun_syslog(LOG_NOTICE,"linkfd begin - host=%p",host); old_prio=getpriority(PRIO_PROCESS,0); setpriority(PRIO_PROCESS,0,LINKFD_PRIO); @@ -419,5 +420,6 @@ setpriority(PRIO_PROCESS,0,old_prio); + vtun_syslog(LOG_NOTICE,"linkfd end - host=%p",host); return linker_term; } --- vtun-3.0.2.orig/tunnel.c +++ vtun-3.0.2/tunnel.c @@ -220,7 +220,9 @@ break; } + vtun_syslog(LOG_NOTICE,"tunnel.c pre - host=%p",host); opt = linkfd(host); + vtun_syslog(LOG_NOTICE,"tunnel.c post - host=%p",host); set_title("%s running down commands", host->host); llist_trav(&host->down, run_cmd, &host->sopt); ---- here is end of patch ---- and everything went smoothly. After killing the client it closed itself without segfaults. My next step was removing mentioned patch and adding DEB_BUILD_OPTIONS=noopt. vtun compiled with -O0 instead of -O2 works correctly and closes without segfault. If you wish to compare binaries I use, I put all of them here: http://hell.pl/arturcz/vtun/ ac0 is default 3.0.2-2 but without dh_strip ac1 is like ac0 but with additional syslog messages (mentioned above patch) ac2 is like ac0 but compiled with -O0 instead of -O2. For compilation of all above I used freshly update pbuilder image of lenny with following gcc version: root@szczaw:/# gcc --version gcc (Debian 4.3.2-1.1) 4.3.2 Copyright (C) 2008 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Best regards Artur -- System Information: Debian Release: 5.0.3 APT prefers proposed-updates APT policy: (500, 'proposed-updates'), (500, 'stable') Architecture: i386 (i686) Kernel: Linux 2.6.26-2-686 (SMP w/2 CPU cores) Locale: LANG=C, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Versions of packages vtun depends on: ii debconf [debconf-2.0] 1.5.24 Debian configuration management sy ii libc6 2.9-6 GNU C Library: Shared libraries ii liblzo2-2 2.03-1 data compression library ii libssl0.9.8 0.9.8g-15+lenny5 SSL shared libraries ii zlib1g 1:1.2.3.3.dfsg-12 compression library - runtime vtun recommends no packages. vtun suggests no packages. -- no debconf information
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--- Begin Message ---Version: 3.0.4-2+rm Dear submitter, as the package vtun has just been removed from the Debian archive unstable we hereby close the associated bug reports. We are sorry that we couldn't deal with your issue properly. For details on the removal, please see https://bugs.debian.org/1090005 The version of this package that was in Debian prior to this removal can still be found using https://snapshot.debian.org/. Please note that the changes have been done on the master archive and will not propagate to any mirrors until the next dinstall run at the earliest. This message was generated automatically; if you believe that there is a problem with it please contact the archive administrators by mailing [email protected]. Debian distribution maintenance software pp. Thorsten Alteholz (the ftpmaster behind the curtain)
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