Given that ERRNO_IS_SECCOMP_FATAL() also matches positive values,
make sure this macro is not called with arguments that do not have
errno semantics.
In this case the arguments passed to ERRNO_IS_SECCOMP_FATAL() are the
values returned by external libseccomp function seccomp_load() which is
not expected to return any positive values, but let's be consistent
anyway and move ERRNO_IS_SECCOMP_FATAL() invocations to the branches
where the return values are known to be negative.
Given that ERRNO_IS_NOT_SUPPORTED() also matches positive values,
make sure this macro is not called with arguments that do not have
errno semantics.
In this case the argument passed to ERRNO_IS_NOT_SUPPORTED() is the
value returned by remount_idmap() which is not expected to return
any positive values, but let's be consistent anyway and move the
ERRNO_IS_NOT_SUPPORTED() invocation to the branch where
the return value is known to be negative.
The check added by 4c27749b8c breaks
booting an arm64 image on x86 using qemu-bin-fmt, so remove it.
Without it, the image built with mkosi --architecture=aarch64
boots fine in nspawn.
When merging the settings we take the pointer to the array of extra
devices, but don't reset the array counter to zero. This later leads to
a NULL pointer dereference, where device_node_array_free() attempts to
loop over a NULL pointer:
+ systemd-nspawn --oci-bundle=/var/lib/machines/testsuite-13.oci-bundle.Npo
../src/nspawn/nspawn-settings.c:118:29: runtime error: member access within null pointer of type 'struct DeviceNode'
#0 0x4b91ee in device_node_array_free ../src/nspawn/nspawn-settings.c:118
#1 0x4ba42a in settings_free ../src/nspawn/nspawn-settings.c:161
#2 0x410b79 in settings_freep ../src/nspawn/nspawn-settings.h:249
#3 0x446ce8 in load_oci_bundle ../src/nspawn/nspawn.c:4733
#4 0x44ff42 in run ../src/nspawn/nspawn.c:5476
#5 0x455296 in main ../src/nspawn/nspawn.c:5919
#6 0x7f0cb7a4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)
#7 0x7f0cb7a4a5c8 in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x275c8)
#8 0x40d284 in _start (/usr/bin/systemd-nspawn+0x40d284)
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../src/nspawn/nspawn-settings.c:118:29 in
Also, add an appropriate assert to catch such issues in the future.
When we're checking if /etc/resolv.conf exists so we can bind mount
on top of it, we care about whether the symlink itself exists if
/etc/resolv.conf exists and not the file it points to, so add
CHASE_NOFOLLOW to make sure we check existence of the symlink and
not the file it points to.
systemd-nspawn now optionally supports colon-separated pair of
host interface name and container interface name for --network-macvlan, --network-ipvlan and --network-interface options.
Also supported in .nspawn configuration files (i.e Interface=, MACVLAN=, IPVLAN= parameters).
man page changed for ntwk interface naming
Previously, when the NULL (all zero) machine ID is configured in the
container, nspawn refused to execute.
Now id128_get_machine() is used, so NULL machine ID is refused with
-ENOMEDIUM, and fallback to specified UUID or randomly generated one.
Otherwise, if getopt() and friends are used before parse_argv(), then
the GNU extensions may be ignored.
This should not change any behavior at least now, as we usually use
getopt_long() only once per invocation. But in the next commit,
getopt_long() will be used for other arrays, hence this change will
become necessary.
Chasing symlinks is a core function that's used in a lot of places
so it deservers a less verbose names so let's rename it to chase()
and chaseat().
We also slightly change the pattern used for the chaseat() helpers
so we get chase_and_openat() and similar.
Whenever we're going to close all file descriptors, we tend to close
the log and set it into open when needed mode. When this is done with
the logging target set to LOG_TARGET_AUTO, we run into issues because
for every logging call, we'll check if stderr is connected to the
journal to determine where to send the logging message. This check
obviously stops working when we close stderr, so we settle the log
target before we do that so that we keep using the same logging
target even after stderr is closed.
@brauner noticed that in invoked containers the root directory is set to
still receive mounts from the host. We should disable that, and
guarantee we live in our own world, because that's what an
(nspawn-style) container *is* after all: a whole new world.
This hence mounts the container subtree to MS_PRIVATE after getting the
root dir in place. Note that this will later be set to MS_SHARED again.
The MS_PRIVATE disconnects mounts from the host, the MS_SHARED then
establishes a new peer group for mount propagation events, so that
payload service managers (such as systemd) can take benefit of
propagation further down the tree.
Since quite a while the propagation from the DDI arch into the
personality() wasn't hooked up anymore. Let's fix that: when the DDI has
a determined arch, automatically propagate this into the personality.
If we're in a user namespace but not unsharing the network namespace,
we won't be able to bind any privileged ports even with
CAP_NET_BIND_SERVICE, so let's drop it from the retained capabilities
so services can condition themselves on that.
Let's port one more over.
Note that this changes behaviour of file_in_same_dir() in some regards.
Specifically, a trailing slash of the input path will be treated
differently: previously we'd operate below that dir then, instead of the
parent. I think that makes little sense however, and I think the code
using this function doesn't expect that either.
Moroever, addresses some corner cases if the path is specified as "/" or
".", i.e. where e cannot extract a parent. These will now be treated as
error, which I think is much cleaner.
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
Also stop stashing the kmsg fifo fd in the socket. Just retrieve it in
the parent and have the parent hold on to it.
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Zbigniew Jędrzejewski-Szmek
Dmitry V. Levin
Lennart Poettering
Daan De Meyer
Luca Boccassi
David Tardon
Frantisek Sumsal
Yu Watanabe
Thierry Martin
Christian Brauner