The fix in 8f1751a111 made me wonder if we could automatically detect
when pointers are accessed but when this might not be safe. Systemd
is already using a lot of `assert(dst)` and this change now forces
us to use them.
So this commit (ab)uses coccinelle to flag any pointer parameter
dereference not preceded by assert(param), ASSERT_PTR(param), or an
explicit NULL check. It adds integration into meson as a new "coccinelle"
test suite (just like clang-tidy) and is run in CI. The check is not
perfect but seems a reasonable heuristic.
For this RFC commit it is scoped to a subset, it excludes 25 dirs right
now and includes around 100. About 300 warnings left. Busywork that I am
happy to do if there is agreement that it is worth it.
With this in place we would have caught the bug from 8f1751a111 in CI:
```
FAIL: check-pointer-deref.cocci found issues in systemd/src/boot:
diff -u -p systemd/src/boot/measure.c /tmp/nothing/measure.c
--- systemd/src/boot/measure.c
+++ /tmp/nothing/measure.c
@@ -312,7 +312,6 @@ EFI_STATUS tpm_log_tagged_event(
if (err != EFI_SUCCESS)
return err;
- *ret_measured = true;
return EFI_SUCCESS;
}
```
This also adds a new POINTER_MAY_BE_NULL() for the cases when the
called function will do the NULL check (like `iovec_is_set()`).
In many cases it's essential to know if the firmware supports a TPM, but
in others we should accept it if the firmware doesn't have TPM support,
in particular if we want to run the OS with a software TPM.
Hence, add tpm2_is_mostly_supported() as function similar to
tpm2_is_fully_supported(), with the only difference that the former
doesn't insist on a firmware supported TPM. Then, change a number of
users over to this (but not all).
Typically, the top-level JSON object has to be an object, in any json
document we parse, hence let's add a simple way to enforce that.
Make use of this in various places.
(Note, various other JSON parsers insist on this logic right from the
beginning, but I actually thinking making this insisting optional like
this patch does it is the cleaner approach)
We often have a pattern where the same verb function is used for
multiple actions. This leads to an antipattern where we figure out what
action needs to be taken from argv[0] multiple times: often once in
parse_argv() to figure out what options are allowed, then once again
implicitly in dispatch_verb(), and then again in the action verb itself.
Let's allow passing a parameter into the verb to simplify this.
This matches a pattern we have in conf-parser.h, where we have both
void *userdata (more global) and void *data (per-config item). Here,
I opted for uintptr_t userdata. It seems that most of the time we'll
want to just pass an enum value. This works OK with no casts. I also
tried a void* and union. In both cases, much more boilerplate is needed:
either a cast or a macro to help avoid compiler warnings. uintptr_t
seems generic enough to cover foreseeable usecases with no fuss.
This is a noop refactoring. See next commit for an example.
Suppress warnings like the following from clang tidy:
```
../src/boot/addon.c:11:19: error: function 'efi_main' can be made static to enforce internal linkage [misc-use-internal-linkage,-warnings-as-errors]
11 | EFIAPI EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *system_table);
| ^
```
Some warnings are suppressed simply by setting comments to ignore the warning,
some are by making global variables static, or include a suitable header.
This does not yet support directory images properly
as systemd itself does not support unpriv directory
images properly yet.
The user profiles are a copy of the system profiles but without
DynamicUser=yes (can't be used by user managers) and without
ProtectHome=yes (this masks /home which breaks StateDirectory= which
is lcoated inside /home)
Let's introduce these for the following two reasons:
- Using them makes sure the parameter names match between declaration
and definition (if both use the corresponding macros).
- They make sure developers can't forget the _const_ and _pure_
attributes for the declarations.
This commit also includes some include sorting fixes
LUKS2 supports built-in integrity checking which may come very handy to
mitigate partial rollback attacks on the storage when only some specific
parts are restored to some old encrypted state. Specific use-cases like
Confidential VMs may want to mandate the usage of feature e.g. on the root
volume. Introduce "encryptedwithintegrity" image policy to support that.
Note, due to the current libcryptsetup limitations, checking whether the
feature is enabled or not for the 'file' case (e.g. DDI image as a raw file)
requires setting up a loop device. To avoid that and keep dissect fully
functional when working unpriviliged, implement a minimal custom LUKS header
parser.
Usually we gracefully ignore unknown configuration parameters, so that
service files can be written by upstreams and used across a variegated
range of distributions with various versions of systemd, to avoid
forcing users to the minimum common denominator and only adding settings
that are supported by the oldest distro supported.
Image policies do not behave like this, and any unknown partition or
policy designator causes the whole unit to fail to parse and a hard
error.
Change it so that parsing RootImagePolicy and friends via unit file or
D-Bus logs but otherwise ignores unknown specifiers, like other options
do.
This allows us to add new specifiers in the future, and users to adopt
them immediately.
Follow-up for d452335aa4
Latest glibc uses _Generic to have strstr() and other functions return
const char* or char* based on whether the input is a const char* or a
char*. This causes build failures as we previously always expected a char*.
Let's fix the compilation failures and add our own macros similar to glibc's
to have string functions that return a mutable or const pointer depending on
the input.
In all cases, everything that we list in 'extract', we also list in
'sources'. We can simplify things by automatically appending the first
list to the second.
In the listings, move 'extract' key right below 'sources', since now
they are both "sources", just with slightly different meanings.
Let's extract common capability parsing code into a generic function
parse_capability_set() with a comprehensive set of unit tests.
We also replace usages of UINT64_MAX with CAP_MASK_UNSET where
applicable and replace the default value of CapabilityBoundingSet
with CAP_MASK_ALL which more clearly identifies that it is initialized
to all capabilities.
AI (copilot) was used to extract the generic function and write the
unit tests, with manual review and fixing afterwards to make sure
everything was correct.
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
When HAVE_SECCOMP is not set, a build error happens:
../src/analyze/analyze-security.c: In function ‘get_security_info’:
../src/analyze/analyze-security.c:2449:13: error: unused variable ‘r’ [-Werror=unused-variable]
2449 | int r;
| ^
cc1: some warnings being treated as errors
Fix it by removing the sometimes unused variable.
The source file uses symbols e.g. execl(), execvp(), _exit(), and so on,
without including unistd.h.
Continuation of 4f18ff2e29.
Follow-up for 9a08000d18.
Related to https://github.com/systemd/systemd/pull/37641.
The name "transient settings" was used in docs/TRANSIENT-SETTINGS.md.
Using "setting" helps distinguish this from D-Bus "properties", which are
a much larger set, partially overlapping.
We use symbols provided by unistd.h without including it. E.g.
open(), close(), read(), write(), access(), symlink(), unlink(), rmdir(),
fsync(), syncfs(), lseek(), ftruncate(), fchown(), dup2(), pipe2(),
getuid(), getgid(), gettid(), getppid(), pipe2(), execv(), _exit(),
environ, STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, F_OK, and their
friends and variants, so on.
Currently, unistd.h is indirectly included mainly in the following two paths:
- through missing_syscall.h, which is planned to covert to .c file.
- through signal.h -> bits/sigstksz.h, which is new since glibc-2.34.
Note, signal.h is included by sd-eevent.h. So, many source files
indirectly include unistd.h if newer glibc is used.
Currently, our baseline on glibc is 2.31. We need to support glibc older
than 2.34, but unfortunately, we do not have any CI environments with
such old glibc. CIFuzz uses glibc-2.31, but it builds only fuzzers, and
many files are even not compiled.
Michael Vogt
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Daan De Meyer
Lennart Poettering
Luca Boccassi
Vitaly Kuznetsov
Luca Boccassi
Zbigniew Jędrzejewski-Szmek
David Tardon
Matteo Croce
Antonio Alvarez Feijoo
ZIHCO