When mount points are stacked, bind_remount_recursive_with_mountinfo()
uses the existing mount options of the "lower" level mount (ie: the
first one that was mounted on a mount point). But the actual mount
point in use is the "top" one (ie: the last one that was mounted on a
mount point), so in practice if the mount options are different between
the layers, the bottom options are used by mistake on the top mount,
which is not what we want. This is because libmount returns the "bottom"
one first.
If the hashmap returns EEXIST, which means the same key (path) with different
value (options) is already present, update the hashmap instead of discarding
the result. This way, the last/top mount options are always used when
mounts are stacked on a mount point.
This was found to cause problems as LXC version 4.x stacks two /sys mounts,
the bottom one read-write and the top one read-only. systemd accidentally
remounts the top-one read-write, breaking various expectations since a
read-only /sys is the way we decide whether we are running in a container
or not (in this particular case, networkd tests are broken as networkd
expects to be able to modify network settings with a writable /sys).
Future versions of LXC will no longer do this double-stacking, but we
need to support running inside older versions too.
This was triggered by https://github.com/systemd/systemd/commit/6720e356c137
as that causes a recursive remount of '/', which processes '/sys' as one
of the submounts, from make_nosuid(). But it's likely that other combinations
of options could trigger this as well.
Before:
root@systemd-debug:/# systemd-run -t --wait --property ProtectSystem=yes findmnt
Running as unit: run-u9.service
Press ^] three times within 1s to disconnect TTY.
TARGET SOURCE FSTYPE OPTIONS
/ /dev/sda2[/var/lib/lxc/systemd-debug/rootfs]
│ ext4 ro,nosuid,relatime,errors=remount-ro,stripe=
├─/dev none tmpfs rw,nosuid,relatime,size=492k,mode=755
│ ├─/dev/.lxc/proc proc proc rw,nosuid,relatime
│ ├─/dev/.lxc/sys sys sysfs rw,nosuid,relatime
│ ├─/dev/console devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/pts devpts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/ptmx devpts[/ptmx] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/tty1 devpts[/0] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/tty2 devpts[/1] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/tty3 devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/tty4 devpts[/3] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptm
│ ├─/dev/shm tmpfs tmpfs rw,nosuid,nodev
│ ├─/dev/hugepages hugetlbfs hugetlbfs rw,nosuid,relatime,pagesize=2M
│ └─/dev/mqueue mqueue mqueue rw,nosuid,nodev,noexec,relatime
├─/proc proc proc rw,nosuid,nodev,noexec,relatime
│ ├─/proc/sys proc[/sys] proc ro,nosuid,nodev,noexec,relatime
│ │ ├─/proc/sys/net proc[/sys/net] proc rw,nosuid,nodev,noexec,relatime
│ │ └─/proc/sys/kernel/random/boot_id
│ │ none[/.lxc-boot-id] tmpfs ro,nosuid,nodev,noexec,relatime,size=492k,mo
│ └─/proc/sysrq-trigger proc[/sysrq-trigger] proc ro,nosuid,nodev,noexec,relatime
├─/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
│ └─/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/devices/virtual/net sysfs sysfs rw,relatime
│ │ └─/sys/devices/virtual/net
│ │ sysfs[/devices/virtual/net] sysfs rw,nosuid,relatime
│ ├─/sys/fs/fuse/connections fusectl fusectl rw,nosuid,nodev,noexec,relatime
│ └─/sys/fs/cgroup cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,m
├─/run tmpfs tmpfs ro,nosuid,nodev,size=4912348k,nr_inodes=8192
│ ├─/run/credentials tmpfs[/systemd/inaccessible/dir] tmpfs ro,nosuid,nodev,noexec,size=4912348k,nr_inod
│ └─/run/systemd/incoming tmpfs[/systemd/propagate/run-u9.service]
│ tmpfs ro,nosuid,nodev,size=4912348k,nr_inodes=8192
├─/tmp tmpfs tmpfs rw,nosuid,nodev,size=12280872k,nr_inodes=409
│ └─/tmp tmpfs[/systemd-private-b730df90da424397a3f246cb15dcdbb1-run-u9.service-K6EUwf/tmp]
│ tmpfs rw,nosuid,nodev,size=12280872k,nr_inodes=409
└─/var/tmp /dev/sda2[/var/lib/lxc/systemd-debug/rootfs/var/tmp/systemd-private-b730df90da424397a3f246cb15dcdbb1-run-u9.service-vEHyRi/tmp]
ext4 rw,nosuid,relatime,errors=remount-ro,stripe=
Finished with result: success
Main processes terminated with: code=exited/status=0
Service runtime: 14.249s
CPU time consumed: 37ms
After:
root@systemd-debug:/# systemd-run -t --wait --property ProtectSystem=yes findmnt
Running as unit: run-u3.service
Press ^] three times within 1s to disconnect TTY.
TARGET SOURCE FSTYPE OPTIONS
/ /dev/sda2[/var/lib/lxc/systemd-debug/rootfs]
│ ext4 rw,relatime,errors=remount-ro,stripe=32699
├─/dev none tmpfs rw,relatime,size=492k,mode=755
│ ├─/dev/.lxc/proc proc proc rw,relatime
│ ├─/dev/.lxc/sys sys sysfs rw,relatime
│ ├─/dev/console devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/pts devpts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/ptmx devpts[/ptmx] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/tty1 devpts[/0] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/tty2 devpts[/1] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/tty3 devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/tty4 devpts[/3] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode
│ ├─/dev/shm tmpfs tmpfs rw,nosuid,nodev
│ ├─/dev/hugepages hugetlbfs hugetlbfs rw,relatime,pagesize=2M
│ └─/dev/mqueue mqueue mqueue rw,nosuid,nodev,noexec,relatime
├─/proc proc proc rw,nosuid,nodev,noexec,relatime
│ ├─/proc/sys proc[/sys] proc ro,nosuid,nodev,noexec,relatime
│ │ ├─/proc/sys/net proc[/sys/net] proc rw,nosuid,nodev,noexec,relatime
│ │ └─/proc/sys/kernel/random/boot_id
│ │ none[/.lxc-boot-id] tmpfs ro,nosuid,nodev,noexec,relatime,size=492k,mode=75
│ └─/proc/sysrq-trigger proc[/sysrq-trigger] proc ro,nosuid,nodev,noexec,relatime
├─/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
│ └─/sys sysfs sysfs ro,nosuid,nodev,noexec,relatime
│ ├─/sys/devices/virtual/net sysfs sysfs rw,relatime
│ │ └─/sys/devices/virtual/net
│ │ sysfs[/devices/virtual/net] sysfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/fs/fuse/connections fusectl fusectl rw,nosuid,nodev,noexec,relatime
│ └─/sys/fs/cgroup cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory
├─/run tmpfs tmpfs rw,nosuid,nodev,size=4912348k,nr_inodes=819200,mo
│ ├─/run/credentials tmpfs[/systemd/inaccessible/dir]
│ │ tmpfs ro,nosuid,nodev,noexec,size=4912348k,nr_inodes=81
│ └─/run/systemd/incoming tmpfs[/systemd/propagate/run-u3.service]
│ tmpfs ro,nosuid,nodev,size=4912348k,nr_inodes=819200,mo
├─/tmp tmpfs tmpfs rw,nosuid,nodev,size=12280872k,nr_inodes=409600
├─/boot /dev/sda2[/var/lib/lxc/systemd-debug/rootfs/boot]
│ ext4 ro,relatime,errors=remount-ro,stripe=32699
└─/usr /dev/sda2[/var/lib/lxc/systemd-debug/rootfs/usr]
ext4 ro,relatime,errors=remount-ro,stripe=32699
Finished with result: success
Main processes terminated with: code=exited/status=0
Service runtime: 14ms
CPU time consumed: 5ms
Host (LXC):
root@systemd-debug:/# findmnt
TARGET SOURCE FSTYPE OPTIONS
/ /dev/sda2[/var/lib/lxc/systemd-debug/rootfs]
│ ext4 rw,relatime,errors=remount-ro,stripe=32699
├─/run tmpfs tmpfs rw,nosuid,nodev,size=4912348k,nr_inodes=819200,mode=755
├─/tmp tmpfs tmpfs rw,nosuid,nodev,size=12280872k,nr_inodes=409600
├─/dev none tmpfs rw,relatime,size=492k,mode=755
│ ├─/dev/pts devpts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/ptmx devpts[/ptmx] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/tty1 devpts[/0] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/tty2 devpts[/1] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/tty3 devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/tty4 devpts[/3] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666,ma
│ ├─/dev/shm tmpfs tmpfs rw,nosuid,nodev
│ ├─/dev/hugepages hugetlbfs hugetlbfs rw,relatime,pagesize=2M
│ ├─/dev/mqueue mqueue mqueue rw,nosuid,nodev,noexec,relatime
│ ├─/dev/console devpts[/2] devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000
│ ├─/dev/.lxc/proc proc proc rw,relatime
│ └─/dev/.lxc/sys sys sysfs rw,relatime
├─/proc proc proc rw,nosuid,nodev,noexec,relatime
│ ├─/proc/sys proc[/sys] proc ro,nosuid,nodev,noexec,relatime
│ │ ├─/proc/sys/kernel/random/boot_id
│ │ │ none[/.lxc-boot-id] tmpfs ro,nosuid,nodev,noexec,relatime,size=492k,mode=755
│ │ └─/proc/sys/net proc[/sys/net] proc rw,nosuid,nodev,noexec,relatime
│ └─/proc/sysrq-trigger proc[/sysrq-trigger] proc ro,nosuid,nodev,noexec,relatime
└─/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
└─/sys sysfs sysfs ro,nosuid,nodev,noexec,relatime
├─/sys/devices/virtual/net sysfs sysfs rw,relatime
│ └─/sys/devices/virtual/net
│ sysfs[/devices/virtual/net]
│ sysfs rw,nosuid,nodev,noexec,relatime
├─/sys/fs/fuse/connections fusectl fusectl rw,nosuid,nodev,noexec,relatime
└─/sys/fs/cgroup cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recurs
Fixes https://github.com/systemd/systemd/issues/20032
This reverts commit cb0e818f7c.
After this was merged, some design and implementation issues were discovered,
see the discussion in #18782 and #19385. They certainly can be fixed, but so
far nobody has stepped up, and we're nearing a release. Hopefully, this feature
can be merged again after a rework.
Fixes#19345.
This graphic chip doesn't have a DRM driver and fallback to vesa-framebuffer
driver.
Without this patch, users of such chip suddenly see their GUI broken without
any indication or reason of what happened (no error message). Hence this
regression is near to impossible to troubleshoot for end users.
Add ip protocol token to SocketBind{Allow|Deny}= property parser.
Use parse_socket_bind_item helper.
Replace int32_t with int in cgroup item for socket-bind as it was
requested in [0].
Update tests.
[0] https://github.com/systemd/systemd/pull/19942#discussion_r652150024
Parse address family, ip protocol and ports, any of them can be
optional. If neither is specified, a special value 'any' is expected.
Helper is placed in shared to be reused in both fragment and dbus.
Add unit tests with valid and invalid examples.
Thin wrappers of ip_protocol_{from|to}_name targeting IPPROTO_TCP and
IPPROTO_UDP only.
Used to parse IP protocol configuration restricted only to TCP and UDP,
e.g. in SocketBind{Allow|Deny}= unit property.
These helpers are inspired by af_{from|to}_ipv4_ipv6 and potentially
extendable with other IP protocols if there is a use-case to expose
them.
Lookup ip protocol in a socket address to allow or deny binding a socket
to the address.
Matching rule is extended with 'protocol' field. If its value is 0
(IPPROTO_IP) ip protocol comparison is omitted and matching is passed to
the next token which is ip ports.
Documentation is updated.
dns_resource_record_copy() assumes that NSEC types bitmap is non-empty
which results in a null pointer dereference inside bitmap_copy() in some
cases. Fix this by calling bitmap_copy() conditionally.
socket_broadcast_group_unref() is only called in netlink_slot_disconnect(),
so the assertion should not be triggered as the match slot was
successfully created.
But, we usually design `_ref/unref()` functions as they can be called
for any inputs. So, let's also follow the design rule here.
Zbigniew Jędrzejewski-Szmek
Luca Boccassi
Franck Bui
Yu Watanabe
Anita Zhang
laineantti
Albert Brox
Julia Kartseva
Dan Streetman
Raul Tambre
Alexander Tsoy
dgcampea