Hello, I am no maintainer, just tried to reproduce this issue which I could inside a minimal Bullseye amd64 qemu VM with the instructions from the linked Ubuntu bug.
I could not reproduce it within Bookworm or Trixie/testing. Without "LogLevel DEBUG" it was also not observable. Unfortunately did also not happen with a ssh package built with asan enabled. And I upgraded step by step via snapshot.d.o, around 2021-11-15 it stopped to be an issue. This step brought openssh 8.7p1-1. Downgrading just openssh 8.4p1-6 in this exact VM showed it again. Therefore I assume this issue got fixed between openssh 8.4p1-6 and 8.7p1-1. Kind regards, Bernhard #13 <signal handler called> #14 malloc_consolidate (av=av@entry=0x7faa3b64cb80 <main_arena>) at malloc.c:4518 #15 0x00007faa3b5023d5 in _int_malloc (av=av@entry=0x7faa3b64cb80 <main_arena>, bytes=bytes@entry=8193) at malloc.c:3699 #16 0x00007faa3b503063 in malloc_check (sz=8192, caller=<optimized out>) at hooks.c:239 #17 0x00007faa3b504cea in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3387 #18 0x00007faa3b4f6ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffe636eb6e0, sizeloc=sizeloc@entry=0x7ffe636eb6e8) at memstream.c:83 #19 0x00007faa3b5726e1 in __vsyslog_internal (pri=39, fmt=0x55b451dcb150 "%.500s", ap=0x7ffe636eb7d0, mode_flags=2) at ../misc/syslog.c:181 #20 0x00007faa3b572d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x55b451dcb150 "%.500s") at ../misc/syslog.c:136 #21 0x000055b451d87e16 in syslog (__fmt=0x55b451dcb150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #22 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x55b451dba421 "Forked child %ld.", args=args@entry=0x7ffe636ec110) at ../../log.c:484 #23 0x000055b451d88254 in debug (fmt=fmt@entry=0x55b451dba421 "Forked child %ld.") at ../../log.c:229 #24 0x000055b451d3c86e in server_accept_loop (config_s=0x7ffe636ec270, newsock=<synthetic pointer>, sock_out=<synthetic pointer>, sock_in=<synthetic pointer>) at ../../sshd.c:1377 #25 main (ac=<optimized out>, av=<optimized out>) at ../../sshd.c:2089
# 2024-04-23 Bullseye/stable amd64 qemu VM apt update apt dist-upgrade apt install systemd-coredump moreutils parallel htop fakeroot mc ccache gdb openssh-server-dbgsym apt build-dep glibc apt build-dep openssh-server mkdir /home/benutzer/source/glibc/orig -p cd /home/benutzer/source/glibc/orig apt source glibc mkdir /home/benutzer/source/openssh-server/orig -p cd /home/benutzer/source/openssh-server/orig apt source openssh-server sed -i.bak 's/#LogLevel INFO/LogLevel DEBUG/g' /etc/ssh/sshd_config systemctl restart sshd ssh-keygen -b 4096 ssh-copy-id -i .ssh/id_rsa.pub benutzer@localhost parallel -j 32 -N0 "ssh benutzer@localhost 'true'" ::: {1..20000} benutzer@debian:~/.ssh$ ssh-keygen -b 4096 Generating public/private rsa key pair. Enter file in which to save the key (/home/benutzer/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/benutzer/.ssh/id_rsa Your public key has been saved in /home/benutzer/.ssh/id_rsa.pub The key fingerprint is: SHA256:Hgx6dUtFBhKiI0wBYKtXMkwZeRcP/eEZCUsU69bbO+o benutzer@debian The key's randomart image is: +---[RSA 4096]----+ |+o== ++B+.++ | |.=+ ...=.++o | | .*.+.. =oo+ | |. = o = ++. | |. . . . S o | | . . o . o | | . . . | | .. | | .E... | +----[SHA256]-----+ benutzer@debian:~$ ssh-copy-id -i .ssh/id_rsa.pub benutzer@localhost /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: ".ssh/id_rsa.pub" /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys benutzer@localhost's password: Number of key(s) added: 1 Now try logging into the machine, with: "ssh 'benutzer@localhost'" and check to make sure that only the key(s) you wanted were added. parallel -j 800 -N0 "ssh benutzer@localhost 'mount; sleep 1; cat /proc/cpuinfo; free -h; dd if=/dev/zero of=/dev/null bs=1 count=8192; mount -av; sleep $(($RANDOM % 5)); lscpu'" ::: {1..10000} # AMD Ryzen 1700, VM, 16 threads root@debian:~# coredumpctl list TIME PID UID GID SIG COREFILE EXE Tue 2024-04-23 00:20:53 CEST 124297 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 00:23:02 CEST 159284 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 00:23:47 CEST 229261 0 0 11 present /usr/sbin/sshd Tue 2024-04-23 00:24:32 CEST 277265 0 0 11 present /usr/sbin/sshd Tue 2024-04-23 00:24:54 CEST 301567 0 0 6 present /usr/sbin/sshd root@debian:~# coredumpctl gdb 301567 PID: 301567 (sshd) UID: 0 (root) GID: 0 (root) Signal: 6 (ABRT) Timestamp: Tue 2024-04-23 00:24:53 CEST (47s ago) Command Line: sshd: /usr/sbin/sshd -D [listener] 4 of 10-100 startups Executable: /usr/sbin/sshd Control Group: /system.slice/ssh.service Unit: ssh.service Slice: system.slice Boot ID: 1fd259cc2ed747a9aaef76e977b483f0 Machine ID: a149817c9a8c4bbda2c4be3e7ba0d6ed Hostname: debian Storage: /var/lib/systemd/coredump/core.sshd.0.1fd259cc2ed747a9aaef76e977b483f0.301567.1713824693000000.zst Message: Process 301567 (sshd) of user 0 dumped core. Stack trace of thread 301567: #0 0x00007ff6d30c9ce1 __GI_raise (libc.so.6 + 0x38ce1) #1 0x00007ff6d30b3537 __GI_abort (libc.so.6 + 0x22537) #2 0x00007ff6d310b3e8 __libc_message (libc.so.6 + 0x7a3e8) #3 0x00007ff6d31126da malloc_printerr (libc.so.6 + 0x816da) #4 0x00007ff6d31159f4 _int_malloc (libc.so.6 + 0x849f4) #5 0x00007ff6d3117b51 __libc_calloc (libc.so.6 + 0x86b51) #6 0x00007ff6d3109ef4 __GI___open_memstream (libc.so.6 + 0x78ef4) #7 0x00007ff6d31856e1 __vsyslog_internal (libc.so.6 + 0xf46e1) #8 0x00007ff6d3185d5f __syslog_chk (libc.so.6 + 0xf4d5f) #9 0x0000555e8e15ee16 n/a (sshd + 0x5ae16) #10 0x0000555e8e15f254 n/a (sshd + 0x5b254) #11 0x0000555e8e1154b6 n/a (sshd + 0x114b6) #12 0x00007ff6d30c9d60 __restore_rt (libc.so.6 + 0x38d60) #13 0x00007ff6d31134b8 malloc_consolidate (libc.so.6 + 0x824b8) #14 0x00007ff6d31153d5 _int_malloc (libc.so.6 + 0x843d5) #15 0x00007ff6d3117b51 __libc_calloc (libc.so.6 + 0x86b51) #16 0x00007ff6d3109ef4 __GI___open_memstream (libc.so.6 + 0x78ef4) #17 0x00007ff6d31856e1 __vsyslog_internal (libc.so.6 + 0xf46e1) #18 0x00007ff6d3185d5f __syslog_chk (libc.so.6 + 0xf4d5f) #19 0x0000555e8e15ee16 n/a (sshd + 0x5ae16) #20 0x0000555e8e15f254 n/a (sshd + 0x5b254) #21 0x0000555e8e11386e n/a (sshd + 0xf86e) #22 0x00007ff6d30b4d0a __libc_start_main (libc.so.6 + 0x23d0a) #23 0x0000555e8e1151ba n/a (sshd + 0x111ba) GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git ... Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/sbin/sshd... (No debugging symbols found in /usr/sbin/sshd) [New LWP 301567] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `sshd: /usr/sbin/ss'. Program terminated with signal SIGABRT, Aborted. #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 50 ../sysdeps/unix/sysv/linux/raise.c: Datei oder Verzeichnis nicht gefunden. (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007ff6d30b3537 in __GI_abort () at abort.c:79 #2 0x00007ff6d310b3e8 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7ff6d3229390 "%s\n") at ../sysdeps/posix/libc_fatal.c:155 #3 0x00007ff6d31126da in malloc_printerr (str=str@entry=0x7ff6d322bbb8 "malloc(): unsorted double linked list corrupted") at malloc.c:5347 #4 0x00007ff6d31159f4 in _int_malloc (av=av@entry=0x7ff6d325fb80 <main_arena>, bytes=bytes@entry=8192) at malloc.c:3744 #5 0x00007ff6d3117b51 in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3428 #6 0x00007ff6d3109ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffc3c8f8630, sizeloc=sizeloc@entry=0x7ffc3c8f8638) at memstream.c:83 #7 0x00007ff6d31856e1 in __vsyslog_internal (pri=39, fmt=0x555e8e1a2150 "%.500s", ap=0x7ffc3c8f8720, mode_flags=2) at ../misc/syslog.c:181 #8 0x00007ff6d3185d5f in __syslog_chk (pri=<optimized out>, flag=<optimized out>, fmt=<optimized out>) at ../misc/syslog.c:136 #9 0x0000555e8e15ee16 in ?? () #10 0x0000555e8e15f254 in ?? () #11 0x0000555e8e1154b6 in ?? () #12 <signal handler called> #13 malloc_consolidate (av=av@entry=0x7ff6d325fb80 <main_arena>) at malloc.c:4511 #14 0x00007ff6d31153d5 in _int_malloc (av=av@entry=0x7ff6d325fb80 <main_arena>, bytes=bytes@entry=8192) at malloc.c:3699 #15 0x00007ff6d3117b51 in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3428 #16 0x00007ff6d3109ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffc3c8f98d0, sizeloc=sizeloc@entry=0x7ffc3c8f98d8) at memstream.c:83 #17 0x00007ff6d31856e1 in __vsyslog_internal (pri=39, fmt=0x555e8e1a2150 "%.500s", ap=0x7ffc3c8f99c0, mode_flags=2) at ../misc/syslog.c:181 #18 0x00007ff6d3185d5f in __syslog_chk (pri=<optimized out>, flag=<optimized out>, fmt=<optimized out>) at ../misc/syslog.c:136 #19 0x0000555e8e15ee16 in ?? () #20 0x0000555e8e15f254 in ?? () #21 0x0000555e8e11386e in ?? () #22 0x00007ff6d30b4d0a in __libc_start_main (main=0x555e8e111cf0, argc=2, argv=0x7ffc3c8fade8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc3c8fadd8) at ../csu/libc-start.c:308 #23 0x0000555e8e1151ba in ?? () (gdb) (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007ff6d30b3537 in __GI_abort () at abort.c:79 #2 0x00007ff6d310b3e8 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7ff6d3229390 "%s\n") at ../sysdeps/posix/libc_fatal.c:155 #3 0x00007ff6d31126da in malloc_printerr (str=str@entry=0x7ff6d322bbb8 "malloc(): unsorted double linked list corrupted") at malloc.c:5347 #4 0x00007ff6d31159f4 in _int_malloc (av=av@entry=0x7ff6d325fb80 <main_arena>, bytes=bytes@entry=8192) at malloc.c:3744 #5 0x00007ff6d3117b51 in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3428 #6 0x00007ff6d3109ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffc3c8f8630, sizeloc=sizeloc@entry=0x7ffc3c8f8638) at memstream.c:83 #7 0x00007ff6d31856e1 in __vsyslog_internal (pri=39, fmt=0x555e8e1a2150 "%.500s", ap=0x7ffc3c8f8720, mode_flags=2) at ../misc/syslog.c:181 #8 0x00007ff6d3185d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x555e8e1a2150 "%.500s") at ../misc/syslog.c:136 #9 0x0000555e8e15ee16 in syslog (__fmt=0x555e8e1a2150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #10 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x555e8e190fbd "main_sigchld_handler: %s", args=args@entry=0x7ffc3c8f9060) at ../../log.c:484 #11 0x0000555e8e15f254 in debug (fmt=fmt@entry=0x555e8e190fbd "main_sigchld_handler: %s") at ../../log.c:229 #12 0x0000555e8e1154b6 in main_sigchld_handler (sig=17) at ../../sshd.c:360 #13 <signal handler called> #14 malloc_consolidate (av=av@entry=0x7ff6d325fb80 <main_arena>) at malloc.c:4511 #15 0x00007ff6d31153d5 in _int_malloc (av=av@entry=0x7ff6d325fb80 <main_arena>, bytes=bytes@entry=8192) at malloc.c:3699 #16 0x00007ff6d3117b51 in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3428 #17 0x00007ff6d3109ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffc3c8f98d0, sizeloc=sizeloc@entry=0x7ffc3c8f98d8) at memstream.c:83 #18 0x00007ff6d31856e1 in __vsyslog_internal (pri=39, fmt=0x555e8e1a2150 "%.500s", ap=0x7ffc3c8f99c0, mode_flags=2) at ../misc/syslog.c:181 #19 0x00007ff6d3185d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x555e8e1a2150 "%.500s") at ../misc/syslog.c:136 #20 0x0000555e8e15ee16 in syslog (__fmt=0x555e8e1a2150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #21 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x555e8e191421 "Forked child %ld.", args=args@entry=0x7ffc3c8fa300) at ../../log.c:484 #22 0x0000555e8e15f254 in debug (fmt=fmt@entry=0x555e8e191421 "Forked child %ld.") at ../../log.c:229 #23 0x0000555e8e11386e in server_accept_loop (config_s=0x7ffc3c8fa460, newsock=<synthetic pointer>, sock_out=<synthetic pointer>, sock_in=<synthetic pointer>) at ../../sshd.c:1377 #24 main (ac=<optimized out>, av=<optimized out>) at ../../sshd.c:2089 (gdb) info thread Id Target Id Frame * 1 Thread 0x7ff6d2c9d900 (LWP 301567) __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 (gdb) root@debian:/var/log# coredumpctl gdb 277265 PID: 277265 (sshd) UID: 0 (root) GID: 0 (root) Signal: 11 (SEGV) Timestamp: Tue 2024-04-23 00:24:32 CEST (17min ago) Command Line: sshd: /usr/sbin/sshd -D [listener] 6 of 10-100 startups Executable: /usr/sbin/sshd Control Group: /system.slice/ssh.service Unit: ssh.service Slice: system.slice Boot ID: 1fd259cc2ed747a9aaef76e977b483f0 Machine ID: a149817c9a8c4bbda2c4be3e7ba0d6ed Hostname: debian Storage: /var/lib/systemd/coredump/core.sshd.0.1fd259cc2ed747a9aaef76e977b483f0.277265.1713824672000000.zst Message: Process 277265 (sshd) of user 0 dumped core. Stack trace of thread 277265: #0 0x00007fb5d3e937a7 _int_free (libc.so.6 + 0x827a7) #1 0x00007fb5d3e965af _int_realloc (libc.so.6 + 0x855af) #2 0x00007fb5d3e97736 __GI___libc_realloc (libc.so.6 + 0x86736) #3 0x00007fb5d3e89e64 _IO_mem_finish (libc.so.6 + 0x78e64) #4 0x00007fb5d3e80efd _IO_new_fclose (libc.so.6 + 0x6fefd) #5 0x00007fb5d3f057e7 __vsyslog_internal (libc.so.6 + 0xf47e7) #6 0x00007fb5d3f05d5f __syslog_chk (libc.so.6 + 0xf4d5f) #7 0x000056494d734e16 n/a (sshd + 0x5ae16) #8 0x000056494d735254 n/a (sshd + 0x5b254) #9 0x000056494d6e986e n/a (sshd + 0xf86e) #10 0x00007fb5d3e34d0a __libc_start_main (libc.so.6 + 0x23d0a) #11 0x000056494d6eb1ba n/a (sshd + 0x111ba) GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git ... Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/sbin/sshd... Reading symbols from /usr/lib/debug/.build-id/d7/1ef5505229d585281cb949a536e6d1c1749a77.debug... [New LWP 277265] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `sshd: /usr/sbin/ss'. Program terminated with signal SIGSEGV, Segmentation fault. #0 _int_free (av=0x7fb5d3fdfb80 <main_arena>, p=0x56494f3bf890, have_lock=<optimized out>) at malloc.c:4341 4341 malloc.c: Datei oder Verzeichnis nicht gefunden. (gdb) bt #0 _int_free (av=0x7fb5d3fdfb80 <main_arena>, p=0x56494f3bf890, have_lock=<optimized out>) at malloc.c:4341 #1 0x00007fb5d3e965af in _int_realloc (av=av@entry=0x7fb5d3fdfb80 <main_arena>, oldp=oldp@entry=0x56494f3bf840, oldsize=oldsize@entry=8208, nb=80) at malloc.c:4644 #2 0x00007fb5d3e97736 in __GI___libc_realloc (oldmem=0x56494f3bf850, bytes=63) at malloc.c:3226 #3 0x00007fb5d3e89e64 in _IO_mem_finish (fp=0x56494f3a5ff0, dummy=<optimized out>) at memstream.c:131 #4 0x00007fb5d3e80efd in _IO_new_fclose (fp=fp@entry=0x56494f3a5ff0) at libioP.h:948 #5 0x00007fb5d3f057e7 in __vsyslog_internal (pri=<optimized out>, fmt=0x56494d778150 "%.500s", ap=0x7fffc4954d70, mode_flags=2) at ../misc/syslog.c:237 #6 0x00007fb5d3f05d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x56494d778150 "%.500s") at ../misc/syslog.c:136 #7 0x000056494d734e16 in syslog (__fmt=0x56494d778150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #8 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x56494d767421 "Forked child %ld.", args=args@entry=0x7fffc49556b0) at ../../log.c:484 #9 0x000056494d735254 in debug (fmt=fmt@entry=0x56494d767421 "Forked child %ld.") at ../../log.c:229 #10 0x000056494d6e986e in server_accept_loop (config_s=0x7fffc4955810, newsock=<synthetic pointer>, sock_out=<synthetic pointer>, sock_in=<synthetic pointer>) at ../../sshd.c:1377 #11 main (ac=<optimized out>, av=<optimized out>) at ../../sshd.c:2089 (gdb) cp -a /etc/default/ssh /etc/default/ssh.orig echo "MALLOC_CHECK_=2" >> /etc/default/ssh parallel -j 15 -N0 "ssh benutzer@localhost 'true'" ::: {1..10000} # AMD Ryzen 1700, VM, 16 threads # MALLOC_CHECK_=2 root@debian:~# coredumpctl list TIME PID UID GID SIG COREFILE EXE ... Tue 2024-04-23 02:46:26 CEST 648738 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:48:17 CEST 652202 0 0 11 present /usr/sbin/sshd Tue 2024-04-23 02:49:26 CEST 694072 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:50:51 CEST 715173 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:50:55 CEST 750581 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:51:41 CEST 753005 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:51:47 CEST 786034 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:51:50 CEST 790574 0 0 6 present /usr/sbin/sshd Tue 2024-04-23 02:51:53 CEST 791146 0 0 6 present /usr/sbin/sshd root@debian:~# coredumpctl gdb 791146 PID: 791146 (sshd) UID: 0 (root) GID: 0 (root) Signal: 6 (ABRT) Timestamp: Tue 2024-04-23 02:51:53 CEST (6h ago) Command Line: sshd: /usr/sbin/sshd -D [listener] 10 of 10-100 startups Executable: /usr/sbin/sshd Control Group: /system.slice/ssh.service Unit: ssh.service Slice: system.slice Boot ID: 1fd259cc2ed747a9aaef76e977b483f0 Machine ID: a149817c9a8c4bbda2c4be3e7ba0d6ed Hostname: debian Storage: /var/lib/systemd/coredump/core.sshd.0.1fd259cc2ed747a9aaef76e977b483f0.791146.1713833513000000.zst Message: Process 791146 (sshd) of user 0 dumped core. Stack trace of thread 791146: #0 0x00007faa3b4b6ce1 __GI_raise (libc.so.6 + 0x38ce1) #1 0x00007faa3b4a0537 __GI_abort (libc.so.6 + 0x22537) #2 0x00007faa3b4f83e8 __libc_message (libc.so.6 + 0x7a3e8) #3 0x00007faa3b4ff6da malloc_printerr (libc.so.6 + 0x816da) #4 0x00007faa3b502b2c _int_malloc (libc.so.6 + 0x84b2c) #5 0x00007faa3b503063 malloc_check (libc.so.6 + 0x85063) #6 0x00007faa3b4f6eca __GI___open_memstream (libc.so.6 + 0x78eca) #7 0x00007faa3b5726e1 __vsyslog_internal (libc.so.6 + 0xf46e1) #8 0x00007faa3b572d5f __syslog_chk (libc.so.6 + 0xf4d5f) #9 0x000055b451d87e16 syslog (sshd + 0x5ae16) #10 0x000055b451d88254 debug (sshd + 0x5b254) #11 0x000055b451d3e4b6 main_sigchld_handler (sshd + 0x114b6) #12 0x00007faa3b4b6d60 __restore_rt (libc.so.6 + 0x38d60) #13 0x00007faa3b5004e0 malloc_consolidate (libc.so.6 + 0x824e0) #14 0x00007faa3b5023d5 _int_malloc (libc.so.6 + 0x843d5) #15 0x00007faa3b503063 malloc_check (libc.so.6 + 0x85063) #16 0x00007faa3b504cea __libc_calloc (libc.so.6 + 0x86cea) #17 0x00007faa3b4f6ef4 __GI___open_memstream (libc.so.6 + 0x78ef4) #18 0x00007faa3b5726e1 __vsyslog_internal (libc.so.6 + 0xf46e1) #19 0x00007faa3b572d5f __syslog_chk (libc.so.6 + 0xf4d5f) #20 0x000055b451d87e16 syslog (sshd + 0x5ae16) #21 0x000055b451d88254 debug (sshd + 0x5b254) #22 0x000055b451d3c86e server_accept_loop (sshd + 0xf86e) #23 0x00007faa3b4a1d0a __libc_start_main (libc.so.6 + 0x23d0a) #24 0x000055b451d3e1ba _start (sshd + 0x111ba) GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git ... Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/sbin/sshd... Reading symbols from /usr/lib/debug/.build-id/d7/1ef5505229d585281cb949a536e6d1c1749a77.debug... [New LWP 791146] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Core was generated by `sshd: /usr/sbin/ss'. Program terminated with signal SIGABRT, Aborted. #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 50 ../sysdeps/unix/sysv/linux/raise.c: Datei oder Verzeichnis nicht gefunden. (gdb) set width 0 (gdb) set pagination off (gdb) bt #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007faa3b4a0537 in __GI_abort () at abort.c:79 #2 0x00007faa3b4f83e8 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7faa3b616390 "%s\n") at ../sysdeps/posix/libc_fatal.c:155 #3 0x00007faa3b4ff6da in malloc_printerr (str=str@entry=0x7faa3b618b80 "malloc(): mismatching next->prev_size (unsorted)") at malloc.c:5347 #4 0x00007faa3b502b2c in _int_malloc (av=av@entry=0x7faa3b64cb80 <main_arena>, bytes=bytes@entry=505) at malloc.c:3741 #5 0x00007faa3b503063 in malloc_check (sz=504, caller=<optimized out>) at hooks.c:239 #6 0x00007faa3b4f6eca in __GI___open_memstream (bufloc=bufloc@entry=0x7ffe636ea430, sizeloc=sizeloc@entry=0x7ffe636ea438) at memstream.c:76 #7 0x00007faa3b5726e1 in __vsyslog_internal (pri=39, fmt=0x55b451dcb150 "%.500s", ap=0x7ffe636ea520, mode_flags=2) at ../misc/syslog.c:181 #8 0x00007faa3b572d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x55b451dcb150 "%.500s") at ../misc/syslog.c:136 #9 0x000055b451d87e16 in syslog (__fmt=0x55b451dcb150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #10 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x55b451db9fbd "main_sigchld_handler: %s", args=args@entry=0x7ffe636eae60) at ../../log.c:484 #11 0x000055b451d88254 in debug (fmt=fmt@entry=0x55b451db9fbd "main_sigchld_handler: %s") at ../../log.c:229 #12 0x000055b451d3e4b6 in main_sigchld_handler (sig=17) at ../../sshd.c:360 #13 <signal handler called> #14 malloc_consolidate (av=av@entry=0x7faa3b64cb80 <main_arena>) at malloc.c:4518 #15 0x00007faa3b5023d5 in _int_malloc (av=av@entry=0x7faa3b64cb80 <main_arena>, bytes=bytes@entry=8193) at malloc.c:3699 #16 0x00007faa3b503063 in malloc_check (sz=8192, caller=<optimized out>) at hooks.c:239 #17 0x00007faa3b504cea in __libc_calloc (n=n@entry=1, elem_size=elem_size@entry=8192) at malloc.c:3387 #18 0x00007faa3b4f6ef4 in __GI___open_memstream (bufloc=bufloc@entry=0x7ffe636eb6e0, sizeloc=sizeloc@entry=0x7ffe636eb6e8) at memstream.c:83 #19 0x00007faa3b5726e1 in __vsyslog_internal (pri=39, fmt=0x55b451dcb150 "%.500s", ap=0x7ffe636eb7d0, mode_flags=2) at ../misc/syslog.c:181 #20 0x00007faa3b572d5f in __syslog_chk (pri=pri@entry=7, flag=flag@entry=1, fmt=fmt@entry=0x55b451dcb150 "%.500s") at ../misc/syslog.c:136 #21 0x000055b451d87e16 in syslog (__fmt=0x55b451dcb150 "%.500s", __pri=7) at /usr/include/x86_64-linux-gnu/bits/syslog.h:31 #22 do_log (level=level@entry=SYSLOG_LEVEL_DEBUG1, fmt=fmt@entry=0x55b451dba421 "Forked child %ld.", args=args@entry=0x7ffe636ec110) at ../../log.c:484 #23 0x000055b451d88254 in debug (fmt=fmt@entry=0x55b451dba421 "Forked child %ld.") at ../../log.c:229 #24 0x000055b451d3c86e in server_accept_loop (config_s=0x7ffe636ec270, newsock=<synthetic pointer>, sock_out=<synthetic pointer>, sock_in=<synthetic pointer>) at ../../sshd.c:1377 #25 main (ac=<optimized out>, av=<optimized out>) at ../../sshd.c:2089 (gdb) frame 14 #14 malloc_consolidate (av=av@entry=0x7faa3b64cb80 <main_arena>) at malloc.c:4518 4518 malloc.c: Datei oder Verzeichnis nicht gefunden. (gdb) display/i $pc 1: x/i $pc => 0x7faa3b5004e0 <malloc_consolidate+160>: mov %rbp,(%rbx,%rbp,1) (gdb) print/x $rbx $1 = 0x55b453395c40 (gdb) print/x $rbp $2 = 0x3620 (gdb) info symbol 0x55b453395c40 No symbol matches 0x55b453395c40. (gdb) print p $3 = (mchunkptr) 0x55b453395c40 (gdb) print *p $4 = {mchunk_prev_size = 504403158265495717, mchunk_size = 13857, fd = 0x7faa3b64cbe0 <main_arena+96>, bk = 0x7faa3b64cbe0 <main_arena+96>, fd_nextsize = 0x0, bk_nextsize = 0x0} (gdb) print/x *p $5 = {mchunk_prev_size = 0x7000000000000a5, mchunk_size = 0x3621, fd = 0x7faa3b64cbe0, bk = 0x7faa3b64cbe0, fd_nextsize = 0x0, bk_nextsize = 0x0} (gdb) directory /home/benutzer/source/glibc/orig/glibc-2.31/malloc export DEB_CFLAGS_APPEND=-fsanitize=address export DEB_CPPFLAGS_APPEND=-fsanitize=address export DEB_CXXFLAGS_APPEND=-fsanitize=address export DEB_LDFLAGS_APPEND='-fsanitize=address -static-libasan' export ASAN_OPTIONS=detect_leaks=0 export PATH=/usr/lib/ccache:$PATH DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage dpkg -i openssh-client_*deb openssh-server_*deb openssh-server-dbgsym_*deb openssh-sftp-server_*deb echo "ASAN_OPTIONS=detect_leaks=0" >> /etc/default/ssh systemctl stop sshd systemctl start sshd # --> Gave no interesting result https://snapshot.debian.org/archive/debian/20210814T212851Z # visible Bullseye Release https://snapshot.debian.org/archive/debian/20210901T090918Z # visible https://snapshot.debian.org/archive/debian/20210915T024357Z # visible https://snapshot.debian.org/archive/debian/20211001T033837Z # visible https://snapshot.debian.org/archive/debian/20211015T025547Z # visible https://snapshot.debian.org/archive/debian/20211101T024700Z # visible https://snapshot.debian.org/archive/debian/20211115T024854Z # visible with 1:8.4p1-6 https://snapshot.debian.org/archive/debian/20211115T024854Z # not visible with 1:8.7p1-1 https://snapshot.debian.org/archive/debian/20220101T000000Z # not visible