Package: systemd
Version: 241-5
Severity: minor
File: /usr/bin/systemd-analyze
Below are two units which both block @debug syscalls (confirmed by strace
crashing).
systemd-analyze incorrectly claims @debug is allowed in one of them.
It seems a "blacklist-only" SystemCallFilter= results in a blacklist in
systemctl show, and systemd-analyze can't understand that?
A "whitelist, then blacklist" SystemCallFilter= results in a whitelist in
systemctl show, which systemd-analyze understands.
bash5$ sudo systemctl daemon-reload
bash5$ sudo systemctl start foo
Job for foo.service failed because a fatal signal was delivered to the
control process.
See "systemctl status foo.service" and "journalctl -xe" for details.
bash5$ sudo systemctl start bar
Job for bar.service failed because a fatal signal was delivered to the
control process.
See "systemctl status bar.service" and "journalctl -xe" for details.
bash5$ journalctl -u foo -u bar -n 100
-- Logs begin at Sat 2019-03-23 01:18:35 AEDT, end at Fri 2063-04-13
13:57:32 AEST. --
Jun 20 17:49:50 goll systemd[1]: Starting foo.service...
Jun 20 17:49:50 goll systemd[1]: foo.service: Main process exited,
code=killed, status=31/SYS
Jun 20 17:49:50 goll systemd[1]: foo.service: Failed with result 'signal'.
Jun 20 17:49:50 goll systemd[1]: Failed to start foo.service.
Jun 20 17:49:52 goll systemd[1]: Starting bar.service...
Jun 20 17:49:52 goll systemd[1]: bar.service: Main process exited,
code=killed, status=31/SYS
Jun 20 17:49:52 goll systemd[1]: bar.service: Failed with result 'signal'.
Jun 20 17:49:52 goll systemd[1]: Failed to start bar.service.
bash5$ systemctl cat foo
# /etc/systemd/system/foo.service
[Service]
Type=oneshot
ExecStart=strace whoami
SystemCallFilter=~@debug @module @mount @raw-io @reboot @swap
@cpu-emulation @obsolete
bash5$ systemctl cat bar
# /etc/systemd/system/bar.service
[Service]
Type=oneshot
ExecStart=strace whoami
SystemCallFilter=@system-service @resources @privileged
SystemCallFilter=~@debug @module @mount @raw-io @reboot @swap
@cpu-emulation @obsolete
bash5$ systemctl show foo | grep SystemCallFilter=
SystemCallFilter=~_sysctl afs_syscall bdflush break chroot create_module
delete_module finit_module ftime get_kernel_syms getpmsg gtty idle init_module
ioperm iopl kexec_file_load kexec_load lock lookup_dcookie modify_ldt mount mpx
pciconfig_iobase pciconfig_read pciconfig_write perf_event_open pivot_root prof
profil ptrace putpmsg query_module reboot rtas s390_pci_mmio_read
s390_pci_mmio_write s390_runtime_instr security sgetmask spu_run ssetmask stty
swapoff swapon switch_endian sysfs tuxcall ulimit umount umount2 uselib ustat
vm86 vm86old vserver
bash5$ systemctl show bar | grep SystemCallFilter=
SystemCallFilter=_llseek _newselect accept accept4 access acct add_key
adjtimex alarm arch_prctl bind bpf brk capget capset chdir chmod chown chown32
clock_adjtime clock_getres clock_gettime clock_nanosleep clock_settime clone
close connect copy_file_range creat dup dup2 dup3 epoll_create epoll_create1
epoll_ctl epoll_ctl_old epoll_pwait epoll_wait epoll_wait_old eventfd eventfd2
execve execveat exit exit_group faccessat fadvise64 fadvise64_64 fallocate
fanotify_init fchdir fchmod fchmodat fchown fchown32 fchownat fcntl fcntl64
fdatasync fgetxattr flistxattr flock fork fremovexattr fsetxattr fstat fstat64
fstatat64 fstatfs fstatfs64 fsync ftruncate ftruncate64 futex futimesat
get_mempolicy get_robust_list get_thread_area getcpu getcwd getdents getdents64
getegid getegid32 geteuid geteuid32 getgid getgid32 getgroups getgroups32
getitimer getpeername getpgid getpgrp getpid getppid getpriority getrandom
getresgid getresgid32 getresuid getresuid32 getrlimit getrusage getsid
getsockname getsockopt gettid gettimeofday getuid getuid32 getxattr
inotify_add_watch inotify_init inotify_init1 inotify_rm_watch io_cancel
io_destroy io_getevents io_setup io_submit ioctl ioprio_get ioprio_set ipc kcmp
keyctl kill lchown lchown32 lgetxattr link linkat listen listxattr llistxattr
lremovexattr lseek lsetxattr lstat lstat64 madvise mbind membarrier
memfd_create migrate_pages mkdir mkdirat mknod mknodat mlock mlock2 mlockall
mmap mmap2 move_pages mprotect mq_getsetattr mq_notify mq_open mq_timedreceive
mq_timedsend mq_unlink mremap msgctl msgget msgrcv msgsnd msync munlock
munlockall munmap name_to_handle_at nanosleep newfstatat nfsservctl nice
oldfstat oldlstat oldolduname oldstat olduname open open_by_handle_at openat
pause personality pipe pipe2 poll ppoll prctl pread64 preadv preadv2 prlimit64
process_vm_readv process_vm_writev pselect6 pwrite64 pwritev pwritev2 quotactl
read readahead readdir readlink readlinkat readv recv recvfrom recvmmsg recvmsg
remap_file_pages removexattr rename renameat renameat2 request_key
restart_syscall rmdir rt_sigaction rt_sigpending rt_sigprocmask rt_sigqueueinfo
rt_sigreturn rt_sigsuspend rt_sigtimedwait rt_tgsigqueueinfo
sched_get_priority_max sched_get_priority_min sched_getaffinity sched_getattr
sched_getparam sched_getscheduler sched_rr_get_interval sched_setaffinity
sched_setattr sched_setparam sched_setscheduler sched_yield select semctl
semget semop semtimedop send sendfile sendfile64 sendmmsg sendmsg sendto
set_mempolicy set_robust_list set_thread_area set_tid_address set_tls
setdomainname setfsgid setfsgid32 setfsuid setfsuid32 setgid setgid32 setgroups
setgroups32 sethostname setitimer setns setpgid setpriority setregid setregid32
setresgid setresgid32 setresuid setresuid32 setreuid setreuid32 setrlimit
setsid setsockopt settimeofday setuid setuid32 setxattr shmat shmctl shmdt
shmget shutdown sigaction sigaltstack signal signalfd signalfd4 sigpending
sigprocmask sigreturn sigsuspend socket socketcall socketpair splice stat
stat64 statfs statfs64 statx stime swapcontext symlink symlinkat sync
sync_file_range syncfs sysinfo tee tgkill time timer_create timer_delete
timer_getoverrun timer_gettime timer_settime timerfd_create timerfd_gettime
timerfd_settime times tkill truncate truncate64 ugetrlimit umask uname unlink
unlinkat unshare userfaultfd utime utimensat utimes vfork vhangup vmsplice
wait4 waitid waitpid write writev
bash5$ systemd-analyze security foo | grep SystemCallFilter=
✗ SystemCallFilter=~@clock System call blacklist defined
for service… 0.2
✗ SystemCallFilter=~@debug System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@module System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@mount System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@raw-io System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@reboot System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@swap System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@privileged System call blacklist defined
for service… 0.2
✗ SystemCallFilter=~@resources System call blacklist defined
for service… 0.2
✗ SystemCallFilter=~@cpu-emulation System call blacklist defined
for service… 0.1
✗ SystemCallFilter=~@obsolete System call blacklist defined
for service… 0.1
bash5$ systemd-analyze security bar | grep SystemCallFilter=
✗ SystemCallFilter=~@clock System call whitelist defined
for service… 0.2
✓ SystemCallFilter=~@debug System call whitelist defined
for service…
✓ SystemCallFilter=~@module System call whitelist defined
for service…
✓ SystemCallFilter=~@mount System call whitelist defined
for service…
✓ SystemCallFilter=~@raw-io System call whitelist defined
for service…
✓ SystemCallFilter=~@reboot System call whitelist defined
for service…
✓ SystemCallFilter=~@swap System call whitelist defined
for service…
✗ SystemCallFilter=~@privileged System call whitelist defined
for service… 0.2
✗ SystemCallFilter=~@resources System call whitelist defined
for service… 0.2
✓ SystemCallFilter=~@cpu-emulation System call whitelist defined
for service…
✓ SystemCallFilter=~@obsolete System call whitelist defined
for service…
-- Package-specific info:
-- System Information:
Debian Release: 10.0
APT prefers testing
APT policy: (990, 'testing'), (500, 'testing-proposed-updates'), (500,
'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 4.19.0-5-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8),
LANGUAGE=en_AU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages systemd depends on:
ii adduser 3.118
ii libacl1 2.2.53-4
ii libapparmor1 2.13.2-10
ii libaudit1 1:2.8.4-3
ii libblkid1 2.33.1-0.1
ii libc6 2.28-10
ii libcap2 1:2.25-2
ii libcryptsetup12 2:2.1.0-5
ii libgcrypt20 1.8.4-5
ii libgnutls30 3.6.7-4
ii libgpg-error0 1.35-1
ii libidn11 1.33-2.2
ii libip4tc0 1.8.2-4
ii libkmod2 26-1
ii liblz4-1 1.8.3-1
ii liblzma5 5.2.4-1
ii libmount1 2.33.1-0.1
ii libpam0g 1.3.1-5
ii libseccomp2 2.3.3-4
ii libselinux1 2.8-1+b1
ii libsystemd0 241-5
ii mount 2.33.1-0.1
ii util-linux 2.33.1-0.1
Versions of packages systemd recommends:
ii dbus 1.12.16-1
ii libpam-systemd 241-5
Versions of packages systemd suggests:
ii policykit-1 0.105-25
pn systemd-container <none>
Versions of packages systemd is related to:
pn dracut <none>
ii initramfs-tools 0.133
ii udev 241-5
-- no debconf information
