Bug#954950: dislocker reports memory access error / segfault after call
Hello Michael, that is great news, just two points I want to mention: If you want to forward information to certain people, please send email to both, the bugs address and the person, e.g. use "reply all" in your mail client. And if you get e.g. "/lib/libdislocker.so.0.7" in your backtrace instead of a real source code line, then you may try to add additional dbgsym packages like in this case libdislocker0.7-dbgsym. And repeat the coredumpctl step, then it should provide better information. But not necessary now as you found the issue already. Kind regards, Bernhard
Bug#954950: dislocker reports memory access error / segfault after call
... the dumps gave the answer: dislocker 0.7.1-5~bpo10+1 depends on libdislocker0.7.1-5~bpo10+1. On the used systems the dependency was not resolved. Instead libdislocker0.7.1-4+b1 was installed, which triggered the crash. Solved, Michael
Bug#954950: dislocker reports memory access error / segfault after call
Dear Bernhard, Journalctrl reveals no more information here. I generated with cordump a trace: syslog report: systemd-coredump[8550]: Process 8548 (dislocker) of user 0 dumped core.#012#012Stack trace of thread 8548:#012#0 0x0bb6 n/a (n/a) systemd[1]: systemd-coredump@1-8549-0.service: Succeeded. coredumpctl report: Reading symbols from /usr/bin/dislocker-fuse...Reading symbols from /usr/lib/debug/.build-id/5a/acaa8ab4f7934ee63e9bc5f643d4e0b6d19432.debug...done. done. warning: core file may not match specified executable file. [New LWP 8548] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `dislocker -V /dev/sdb2 -u -- /media/bitlocker'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x0bb6 in ?? () (gdb) bt #0 0x0bb6 in ?? () #1 0x7fb97f3a3762 in print_one_datum () from /lib/libdislocker.so.0.7 #2 0x7fb97f3a3acc in print_datum_vmk () from /lib/libdislocker.so.0.7 #3 0x7fb97f3a3762 in print_one_datum () from /lib/libdislocker.so.0.7 #4 0x7fb97f3a662b in print_data () from /lib/libdislocker.so.0.7 #5 0x7fb97f3a4ccc in dis_metadata_initialize () from /lib/libdislocker.so.0.7 #6 0x7fb97f3a14dd in dis_initialize () from /lib/libdislocker.so.0.7 #7 0x5654ded9159c in main (argc=6, argv=0x7ffce55e43b8) at ./src/dislocker-fuse.c:229 (gdb) Thanks a lot! Kind regards, Michael On Wed, 25 Mar 2020 23:59:19 +0100 =?UTF-8?Q?Bernhard_=c3=9cbelacker?= wrote: > Hello Michael, > I am not involved in packaging dislocker but might have some points. > > This "error 14" should mean it cannot read from memory the next > instruction to execute. This makes sense as the "ip" or "RIP" has > a value of 0xbb6 which is unlikely to contain program code. > > If it is possible to install e.g. systemd-coredump more details > of any crashes are tried to be collected. > I guess for this kind of crash the output of "journalctl --no-pager" > migth not reveal much more useful information, > but "coredump gdb", with the command "bt" at the "(gdb)" prompt, > might be able to show a reasonable backtrace. > > This would improve if the debug symbols in package > dislocker-dbgsym could be installed, too. > More hints on the debug symbol repositories and this topic > in general are collected in [2]. > > Kind regards, > Bernhard > > [1] https://wiki.debian.org/InterpretingKernelOutputAtProcessCrash > "error 14" == 0x14 == 0n20 == 0b10100 > -> user-mode access, fault was an instruction fetch > > [2] https://wiki.debian.org/HowToGetABacktrace#Installing_the_debugging_symbols > >
Bug#954950: dislocker reports memory access error / segfault after call
Hello Michael, I am not involved in packaging dislocker but might have some points. This "error 14" should mean it cannot read from memory the next instruction to execute. This makes sense as the "ip" or "RIP" has a value of 0xbb6 which is unlikely to contain program code. If it is possible to install e.g. systemd-coredump more details of any crashes are tried to be collected. I guess for this kind of crash the output of "journalctl --no-pager" migth not reveal much more useful information, but "coredump gdb", with the command "bt" at the "(gdb)" prompt, might be able to show a reasonable backtrace. This would improve if the debug symbols in package dislocker-dbgsym could be installed, too. More hints on the debug symbol repositories and this topic in general are collected in [2]. Kind regards, Bernhard [1] https://wiki.debian.org/InterpretingKernelOutputAtProcessCrash "error 14" == 0x14 == 0n20 == 0b10100 -> user-mode access, fault was an instruction fetch [2] https://wiki.debian.org/HowToGetABacktrace#Installing_the_debugging_symbols
Bug#954950: dislocker reports memory access error / segfault after call
Package: dislocker Version: 0.7.1-5~bpo10+1 Severity: important Dear Maintainer, i found an issue with dislocker on my current debian 10 install. - I created different bilocker encrypted partitions in Win10 (NTFS, Win10 Version 1909). - During creation I selected different encryption methods (New encryption mode and compatible mode). - I encrypted used disk space only. - I used internal hard disks and usb memory sticks for the tests. - I tried to mount the partitions on two differnt machines (same linux os) via command "sudo dislocker -V /dev/sdc1 -u -- /media/bitlocker" - I got response "Speicherzugriffsfehler" -> "Memory Access Error" in command line. - I got response "dislocker[7687]: segfault at bb6 ip 0bb6 sp 7ffe7ae992e8 error 14 in dislocker-fuse[55f87f5e7000+1000]" in in syslog - I got response "Code: Bad RIP value." in syslog Had so far no succes to mount a fresh encrypted partion within debian 10. Thank you for your help/support, Kind Regards, Michael W. -- System Information: Debian Release: 10.3 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 5.4.0-0.bpo.4-amd64 (SMP w/24 CPU cores) Kernel taint flags: TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE= (charmap=UTF-8) Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages dislocker depends on: ii libc62.28-10 ii libdislocker0.7 0.7.1-4+b1 ii libfuse2 2.9.9-1 ii libmbedcrypto3 2.16.0-1 ii ruby 1:2.5.1 dislocker recommends no packages. dislocker suggests no packages. -- no debconf information
