Package: libfcgi-perl Version: 0.79+ds-2 Severity: normal I recently upgraded my system from jessie i386 to bullseye amd64. Since I did this, a long-established web application has become flaky (returning no output from requests). Associated with its failures I see log messages like this:
Jul 8 21:59:42 chiark kernel: [354982.615451] perl[7671]: segfault at 22 ip 000055b443da11b1 sp 00007ffe01ca1e50 error 6 in perl[55b443d9d000+185000] The same hardware has been running an amd64 kernel (albeit i386 userland) forever with no unexplained problems, so I trust the hardware. Other Perl programs on the system are fine. I looked through the memory map of a relevant perl process (see below) and I think it very likely that the problem is a bug in libfcgi or in FCGI.so. The failures are intermittent and I don't have a reliable repro. Due to the convoluted arrangements by which this webapp is invoked in my environment, it is not entirely straightforward to get coredumps or stack traces, etc. I can try to provide better information if it is likely to be useful. But first I thought I would ask: is this at all a plausible theory ? Is it worth my time upending everything so that I can get a stack trace or attach a debugger ? My alternative is to reorganise my invocation method entirely. My webapp is in Mason 1 (libhtml-mason-perl), so I think my options may be limited. -- System Information: Debian Release: 11.3 APT prefers stable-security APT policy: (500, 'stable-security'), (500, 'stable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.10.0-15-amd64 (SMP w/8 CPU threads) Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /bin/dash Init: sysvinit (via /sbin/init) LSM: AppArmor: enabled Versions of packages libfcgi-perl depends on: ii libc6 2.31-13+deb11u3 ii libfcgi0ldbl 2.4.2-2 ii perl 5.32.1-4+deb11u2 ii perl-base [perlapi-5.32.0] 5.32.1-4+deb11u2 libfcgi-perl recommends no packages. libfcgi-perl suggests no packages. -- no debconf information 55a3d95e8000-55a3d962f000 r--p 00000000 fe:09 106888 /usr/bin/perl 55a3d962f000-55a3d97b4000 r-xp 00047000 fe:09 106888 /usr/bin/perl 55a3d97b4000-55a3d9959000 r--p 001cc000 fe:09 106888 /usr/bin/perl 55a3d995a000-55a3d9969000 r--p 00371000 fe:09 106888 /usr/bin/perl 55a3d9969000-55a3d996c000 rw-p 00380000 fe:09 106888 /usr/bin/perl 55a3d996c000-55a3d9972000 rw-p 00000000 00:00 0 55a3dafe6000-55a3dc656000 rw-p 00000000 00:00 0 [heap] 7fcfcd97e000-7fcfcde0a000 r--p 00000000 fe:09 213000 /usr/lib/locale/locale-archive 7fcfcde0a000-7fcfcde1a000 r--p 00000000 fe:09 234768 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6 7fcfcde1a000-7fcfcdf12000 r-xp 00010000 fe:09 234768 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6 7fcfcdf12000-7fcfcdf46000 r--p 00108000 fe:09 234768 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6 7fcfcdf46000-7fcfcdf4a000 r--p 0013b000 fe:09 234768 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6 7fcfcdf4a000-7fcfcdf4d000 rw-p 0013f000 fe:09 234768 /usr/lib/x86_64-linux-gnu/libsqlite3.so.0.8.6 7fcfcdf70000-7fcfcdf75000 r--p 00000000 fe:09 306657 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBD/SQLite/SQLite.so 7fcfcdf75000-7fcfcdf8e000 r-xp 00005000 fe:09 306657 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBD/SQLite/SQLite.so 7fcfcdf8e000-7fcfcdf99000 r--p 0001e000 fe:09 306657 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBD/SQLite/SQLite.so 7fcfcdf99000-7fcfcdf9a000 r--p 00028000 fe:09 306657 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBD/SQLite/SQLite.so 7fcfcdf9a000-7fcfcdf9b000 rw-p 00029000 fe:09 306657 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBD/SQLite/SQLite.so 7fcfcdf9b000-7fcfcdfbc000 rw-p 00000000 00:00 0 7fcfcdfbc000-7fcfcdfbf000 r--p 00000000 fe:09 241993 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBI/DBI.so 7fcfcdfbf000-7fcfcdfd7000 r-xp 00003000 fe:09 241993 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBI/DBI.so 7fcfcdfd7000-7fcfcdfdd000 r--p 0001b000 fe:09 241993 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBI/DBI.so 7fcfcdfdd000-7fcfcdfde000 r--p 00020000 fe:09 241993 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBI/DBI.so 7fcfcdfde000-7fcfcdfdf000 rw-p 00021000 fe:09 241993 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/DBI/DBI.so 7fcfcdfdf000-7fcfcdfe1000 r--p 00000000 fe:09 231616 /usr/lib/x86_64-linux-gnu/perl/5.32.1/auto/Data/Dumper/Dumper.so 7fcfcdfe1000-7fcfcdfe7000 r-xp 00002000 fe:09 231616 /usr/lib/x86_64-linux-gnu/perl/5.32.1/auto/Data/Dumper/Dumper.so 7fcfcdfe7000-7fcfcdfe8000 r--p 00008000 fe:09 231616 /usr/lib/x86_64-linux-gnu/perl/5.32.1/auto/Data/Dumper/Dumper.so 7fcfcdfe8000-7fcfcdfe9000 r--p 00008000 fe:09 231616 /usr/lib/x86_64-linux-gnu/perl/5.32.1/auto/Data/Dumper/Dumper.so 7fcfcdfe9000-7fcfcdfea000 rw-p 00009000 fe:09 231616 /usr/lib/x86_64-linux-gnu/perl/5.32.1/auto/Data/Dumper/Dumper.so 7fcfcdfea000-7fcfcdfeb000 r--p 00000000 fe:09 356005 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/BSD/Resource/Resource.so 7fcfcdfeb000-7fcfcdfed000 r-xp 00001000 fe:09 356005 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/BSD/Resource/Resource.so 7fcfcdfed000-7fcfcdfee000 r--p 00003000 fe:09 356005 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/BSD/Resource/Resource.so 7fcfcdfee000-7fcfcdfef000 r--p 00003000 fe:09 356005 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/BSD/Resource/Resource.so 7fcfcdfef000-7fcfcdff0000 rw-p 00004000 fe:09 356005 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/BSD/Resource/Resource.so 7fcfcdff0000-7fcfcdff6000 r--p 00000000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfcdff6000-7fcfce003000 r-xp 00006000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfce003000-7fcfce007000 r--p 00013000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfce007000-7fcfce008000 ---p 00017000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfce008000-7fcfce00b000 r--p 00017000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfce00b000-7fcfce00c000 rw-p 0001a000 fe:09 232078 /usr/lib/x86_64-linux-gnu/perl-base/auto/POSIX/POSIX.so 7fcfce00c000-7fcfce00e000 r--p 00000000 fe:09 232068 /usr/lib/x86_64-linux-gnu/perl-base/auto/File/Glob/Glob.so 7fcfce00e000-7fcfce012000 r-xp 00002000 fe:09 232068 /usr/lib/x86_64-linux-gnu/perl-base/auto/File/Glob/Glob.so 7fcfce012000-7fcfce013000 r--p 00006000 fe:09 232068 /usr/lib/x86_64-linux-gnu/perl-base/auto/File/Glob/Glob.so 7fcfce013000-7fcfce014000 r--p 00006000 fe:09 232068 /usr/lib/x86_64-linux-gnu/perl-base/auto/File/Glob/Glob.so 7fcfce014000-7fcfce015000 rw-p 00007000 fe:09 232068 /usr/lib/x86_64-linux-gnu/perl-base/auto/File/Glob/Glob.so 7fcfce015000-7fcfce017000 r--p 00000000 fe:09 304106 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Params/Validate/XS/XS.so 7fcfce017000-7fcfce020000 r-xp 00002000 fe:09 304106 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Params/Validate/XS/XS.so 7fcfce020000-7fcfce022000 r--p 0000b000 fe:09 304106 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Params/Validate/XS/XS.so 7fcfce022000-7fcfce023000 r--p 0000c000 fe:09 304106 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Params/Validate/XS/XS.so 7fcfce023000-7fcfce024000 rw-p 0000d000 fe:09 304106 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Params/Validate/XS/XS.so 7fcfce024000-7fcfce026000 r--p 00000000 fe:09 240806 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/HTML/Parser/Parser.so 7fcfce026000-7fcfce02e000 r-xp 00002000 fe:09 240806 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/HTML/Parser/Parser.so 7fcfce02e000-7fcfce030000 r--p 0000a000 fe:09 240806 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/HTML/Parser/Parser.so 7fcfce030000-7fcfce031000 r--p 0000b000 fe:09 240806 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/HTML/Parser/Parser.so 7fcfce031000-7fcfce032000 rw-p 0000c000 fe:09 240806 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/HTML/Parser/Parser.so 7fcfce032000-7fcfce034000 r--p 00000000 fe:09 232076 /usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so 7fcfce034000-7fcfce03e000 r-xp 00002000 fe:09 232076 /usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so 7fcfce03e000-7fcfce040000 r--p 0000c000 fe:09 232076 /usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so 7fcfce040000-7fcfce041000 r--p 0000d000 fe:09 232076 /usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so 7fcfce041000-7fcfce042000 rw-p 0000e000 fe:09 232076 /usr/lib/x86_64-linux-gnu/perl-base/auto/List/Util/Util.so 7fcfce042000-7fcfce044000 r--p 00000000 fe:09 232073 /usr/lib/x86_64-linux-gnu/perl-base/auto/IO/IO.so 7fcfce044000-7fcfce046000 r-xp 00002000 fe:09 232073 /usr/lib/x86_64-linux-gnu/perl-base/auto/IO/IO.so 7fcfce046000-7fcfce047000 r--p 00004000 fe:09 232073 /usr/lib/x86_64-linux-gnu/perl-base/auto/IO/IO.so 7fcfce047000-7fcfce048000 r--p 00004000 fe:09 232073 /usr/lib/x86_64-linux-gnu/perl-base/auto/IO/IO.so 7fcfce048000-7fcfce049000 rw-p 00005000 fe:09 232073 /usr/lib/x86_64-linux-gnu/perl-base/auto/IO/IO.so 7fcfce049000-7fcfce04b000 r--p 00000000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce04b000-7fcfce04c000 r-xp 00002000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce04c000-7fcfce04d000 r--p 00003000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce04d000-7fcfce04e000 ---p 00004000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce04e000-7fcfce04f000 r--p 00004000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce04f000-7fcfce050000 rw-p 00005000 fe:09 232064 /usr/lib/x86_64-linux-gnu/perl-base/auto/Fcntl/Fcntl.so 7fcfce050000-7fcfce052000 rw-p 00000000 00:00 0 7fcfce052000-7fcfce054000 r--p 00000000 fe:0c 32984 /lib/x86_64-linux-gnu/libcrypt.so.1.1.0 7fcfce054000-7fcfce069000 r-xp 00002000 fe:0c 32984 /lib/x86_64-linux-gnu/libcrypt.so.1.1.0 7fcfce069000-7fcfce083000 r--p 00017000 fe:0c 32984 /lib/x86_64-linux-gnu/libcrypt.so.1.1.0 7fcfce083000-7fcfce084000 r--p 00030000 fe:0c 32984 /lib/x86_64-linux-gnu/libcrypt.so.1.1.0 7fcfce084000-7fcfce085000 rw-p 00031000 fe:0c 32984 /lib/x86_64-linux-gnu/libcrypt.so.1.1.0 7fcfce085000-7fcfce08d000 rw-p 00000000 00:00 0 7fcfce08d000-7fcfce0b2000 r--p 00000000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce0b2000-7fcfce1fd000 r-xp 00025000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce1fd000-7fcfce247000 r--p 00170000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce247000-7fcfce248000 ---p 001ba000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce248000-7fcfce24b000 r--p 001ba000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce24b000-7fcfce24e000 rw-p 001bd000 fe:0c 33110 /lib/x86_64-linux-gnu/libc-2.31.so 7fcfce24e000-7fcfce252000 rw-p 00000000 00:00 0 7fcfce252000-7fcfce259000 r--p 00000000 fe:0c 33121 /lib/x86_64-linux-gnu/libpthread-2.31.so 7fcfce259000-7fcfce269000 r-xp 00007000 fe:0c 33121 /lib/x86_64-linux-gnu/libpthread-2.31.so 7fcfce269000-7fcfce26e000 r--p 00017000 fe:0c 33121 /lib/x86_64-linux-gnu/libpthread-2.31.so 7fcfce26e000-7fcfce26f000 r--p 0001b000 fe:0c 33121 /lib/x86_64-linux-gnu/libpthread-2.31.so 7fcfce26f000-7fcfce270000 rw-p 0001c000 fe:0c 33121 /lib/x86_64-linux-gnu/libpthread-2.31.so 7fcfce270000-7fcfce274000 rw-p 00000000 00:00 0 7fcfce274000-7fcfce283000 r--p 00000000 fe:0c 33112 /lib/x86_64-linux-gnu/libm-2.31.so 7fcfce283000-7fcfce31d000 r-xp 0000f000 fe:0c 33112 /lib/x86_64-linux-gnu/libm-2.31.so 7fcfce31d000-7fcfce3b6000 r--p 000a9000 fe:0c 33112 /lib/x86_64-linux-gnu/libm-2.31.so 7fcfce3b6000-7fcfce3b7000 r--p 00141000 fe:0c 33112 /lib/x86_64-linux-gnu/libm-2.31.so 7fcfce3b7000-7fcfce3b8000 rw-p 00142000 fe:0c 33112 /lib/x86_64-linux-gnu/libm-2.31.so 7fcfce3b8000-7fcfce3b9000 r--p 00000000 fe:0c 33111 /lib/x86_64-linux-gnu/libdl-2.31.so 7fcfce3b9000-7fcfce3bb000 r-xp 00001000 fe:0c 33111 /lib/x86_64-linux-gnu/libdl-2.31.so 7fcfce3bb000-7fcfce3bc000 r--p 00003000 fe:0c 33111 /lib/x86_64-linux-gnu/libdl-2.31.so 7fcfce3bc000-7fcfce3bd000 r--p 00003000 fe:0c 33111 /lib/x86_64-linux-gnu/libdl-2.31.so 7fcfce3bd000-7fcfce3be000 rw-p 00004000 fe:0c 33111 /lib/x86_64-linux-gnu/libdl-2.31.so 7fcfce3be000-7fcfce3c0000 rw-p 00000000 00:00 0 7fcfce3c0000-7fcfce3c1000 r--p 00000000 fe:09 241343 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Clone/Clone.so 7fcfce3c1000-7fcfce3c2000 r-xp 00001000 fe:09 241343 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Clone/Clone.so 7fcfce3c2000-7fcfce3c3000 r--p 00002000 fe:09 241343 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Clone/Clone.so 7fcfce3c3000-7fcfce3c4000 r--p 00002000 fe:09 241343 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Clone/Clone.so 7fcfce3c4000-7fcfce3c5000 rw-p 00003000 fe:09 241343 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/Clone/Clone.so 7fcfce3c5000-7fcfce3c8000 r--p 00000000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3c8000-7fcfce3ce000 r-xp 00003000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3ce000-7fcfce3d0000 r--p 00009000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3d0000-7fcfce3d1000 ---p 0000b000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3d1000-7fcfce3d2000 r--p 0000b000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3d2000-7fcfce3d3000 rw-p 0000c000 fe:09 233544 /usr/lib/x86_64-linux-gnu/libfcgi.so.0.0.0 7fcfce3d3000-7fcfce3d5000 r--p 00000000 fe:09 304080 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/FCGI/FCGI.so 7fcfce3d5000-7fcfce3da000 r-xp 00002000 fe:09 304080 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/FCGI/FCGI.so 7fcfce3da000-7fcfce3db000 r--p 00007000 fe:09 304080 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/FCGI/FCGI.so 7fcfce3db000-7fcfce3dc000 r--p 00007000 fe:09 304080 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/FCGI/FCGI.so 7fcfce3dc000-7fcfce3dd000 rw-p 00008000 fe:09 304080 /usr/lib/x86_64-linux-gnu/perl5/5.32/auto/FCGI/FCGI.so 7fcfce3dd000-7fcfce3de000 r--p 00000000 fe:09 232062 /usr/lib/x86_64-linux-gnu/perl-base/auto/Cwd/Cwd.so 7fcfce3de000-7fcfce3e0000 r-xp 00001000 fe:09 232062 /usr/lib/x86_64-linux-gnu/perl-base/auto/Cwd/Cwd.so 7fcfce3e0000-7fcfce3e1000 r--p 00003000 fe:09 232062 /usr/lib/x86_64-linux-gnu/perl-base/auto/Cwd/Cwd.so 7fcfce3e1000-7fcfce3e2000 r--p 00003000 fe:09 232062 /usr/lib/x86_64-linux-gnu/perl-base/auto/Cwd/Cwd.so 7fcfce3e2000-7fcfce3e3000 rw-p 00004000 fe:09 232062 /usr/lib/x86_64-linux-gnu/perl-base/auto/Cwd/Cwd.so 7fcfce3e3000-7fcfce3e4000 r--p 00000000 fe:0c 33106 /lib/x86_64-linux-gnu/ld-2.31.so 7fcfce3e4000-7fcfce404000 r-xp 00001000 fe:0c 33106 /lib/x86_64-linux-gnu/ld-2.31.so 7fcfce404000-7fcfce40c000 r--p 00021000 fe:0c 33106 /lib/x86_64-linux-gnu/ld-2.31.so 7fcfce40d000-7fcfce40e000 r--p 00029000 fe:0c 33106 /lib/x86_64-linux-gnu/ld-2.31.so 7fcfce40e000-7fcfce40f000 rw-p 0002a000 fe:0c 33106 /lib/x86_64-linux-gnu/ld-2.31.so 7fcfce40f000-7fcfce410000 rw-p 00000000 00:00 0 7ffe30084000-7ffe300a5000 rw-p 00000000 00:00 0 [stack] 7ffe300d4000-7ffe300d8000 r--p 00000000 00:00 0 [vvar] 7ffe300d8000-7ffe300da000 r-xp 00000000 00:00 0 [vdso]