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()`).
So far we always conditioned our TPM magic on the UKI having detected
TPM support in the firmware. This is a bit limiting when we want to
support a software TPM that is not visible to the firmware. Hence let's
split this up, and add a separate control that can be set via the kernel
command line. However, as before, let's by default inherit the firmare
TPM discovery state into it, to retain the current behaviour unless
overriden.
With this in place, boot with "systemd.tpm2_measured_os=1
systemd.tpm2_software_fallback=1" on the kernel cmdline to get the swtpm
fallback and then a measured OS based on it.
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.
Add the libfido2 dependency to cryptenroll and cryptsetup's
meson files. If libfido2's not installed in the default path
the build wasn't finding its headers correctly.
When 'tpm2-primary-alg' is missing in LUKS JSON token, the output of
'cryptsetup luksDump' is always:
tpm2-primary-alg: ecc
because tpm2_parse_luks2_json() returns the default (TPM2_ALG_ECC). This can be
misleading and wrong. Make tpm2_parse_luks2_json() return the reality and move
the default to tpm2_unseal().
Let's pick the default NvPCR name to use inside of cryptsetup itself, instead
of in the generator. I think this is the better choice, since it means
the default can also be used if the regular verittab generator is used
instead of the gpt-auto generator.
The expected hash (SHA265 HMAC signature) uses the exact same algorithm which
is used to calculate sha256 PCR bank digest when 'tpm2-measure-pcr=' is used.
Calling mlockall in an unprivileged process most notably had the effect
of making systemd-cryptenroll OOM while trying to open a normal-sized
argon2 keyslot due to it hitting RLIMIT_MEMLOCK.
When employing MCL_FUTURE we don't actually want it to impose
immediate population of malloc()-ed pages. Hence let's set
MCL_ONFAULT everywhere.
Additionally, specify MCL_CURRENT to ensure future memory allocations
on already mapped pages are covered too. (Addresses
https://github.com/systemd/systemd/pull/40319#discussion_r2693726196)
Note that in shutdown the mlockall() is done to avoid keeping swap space
busy, hence a dedicated call w/ MCL_CURRENT and w/o MCL_ONFAULT is made.
Major distributions already have cryptsetup newer than 2.4.0.
Let's bump the minimal required version.
Note, cryptsetup 2.4.0 was released on 2021-08-18.
See also #38608.
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.
Currently, if the libmount feature is disabled, we don't build
libshared and as a result skip building every other executable as
well. Among other things, this makes our nodeps CI builds kind of
pointless since hardly any code will be compiled.
Let's improve on the situation by making libmount properly optional
in libshared. Then, we only skip building the executables that
actually need libmount.
We soon want to add the ability to extend into nvindexes in addition to
PCRs, hence rename the function to make clear it is about pcr extension.
While we are at it, switch things over to "struct iovec" as we generally
try to do it now in tpm2-util.[ch] these days.
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.
Now that we have recognizable errors, let's print clear error messages
when we try to unlock a TPM slot. And in case of the token plugin
propagate this as ENOANO so that libcryptsetup recognizes this as bad
PIN. (ENOANO is documented as the error to return in that case)
Fixes: #32260
meson by default adds the current source and build directory as include
directories. Because we structure our meson code by gathering a giant dict
of everything we want to do and then doing all the actual target generation
in the top level meson.build, this behavior does not make sense at all because
we end up adding the top level repository directory as an include directory
which is never what we want.
At the same time, let's also make sure the top level directory of the build
directory is not an include directory, by moving the version.h generation
into the src/version subdirectory and then adding the src/version subdirectory
of the build directory as an include directory instead of the top level
repository directory.
Making this change means that language servers such as clangd can't get
confused when they automatically insert an #include line and insert
"#include "src/basic/fs-util.h" instead of "#include "fs-util.h".
abs() requires including the entirety of stdlib.h just for a single
trivial function. Let's introduce the ABS() macro and use it in header
files instead so we can get rid of stdlib.h transitive includes in header
files in a later commit.
Let's move some logic from _DEFINE_MAIN_FUNCTION() and other places
in main-func.h into functions that we implement in main-func.c to
allow moving some included headers from the header to the .c file.
This code seems to not be used anywhere at all, so let's drop it.
Follow up for ba8d00e859
Follow up for 85686b37b0
Follow up for aff853f8ea
Follow up for 36dad381a2
Now that the necessary functions from log.h have been moved to macro.h,
we can stop including log.h in macro.h. This requires modifying source
files all over the tree to include log.h instead.
This introduce `LOG_ITEM()` macro that checks format strings in
log_struct() and friends.
Hopefully, this silences false-positive warnings by Coverity.
Let's improve error handling in case one tries to unlock a TPM2 locked
volume on a different machine via TPM than it was originally enrolled
on. Let's recognize this case and print a clearer error message.
This introduce LOG_ITEM() macro that checks arbitrary formats in
log_struct().
Then, drop _printf_ attribute from log_struct_internal(), as it does not
help so much, and compiler checked only the first format string.
Hopefully, this silences false-positive warnings by Coverity.
Now our baseline of meson is 0.62, hence install_symlink() can be used.
Note, install_symlink() implies install_emptydir() for specified
install_dir. Hence, this also drops several unnecessary
install_emptydir() calls.
Note, the function currently does not support 'relative' and 'force' flags,
so several 'ln -frsT' inline calls cannot be replaced.
PCR 7 covers the SecureBoot policy, in particular "dbx", i.e. the
denylist of bad actors. That list is pretty much as frequently updated
as firmware these days (as fwupd took over automatic updating). This
means literal PCR 7 policies are problematic: they likely break soon,
and are as brittle as any other literal PCR policies.
hence, pick safer defaults, i.e. exclude PCR 7 from the default mask.
This means the mask is now empty.
Generally, people should really switch to signed PCR policies covering
PCR 11, in combination with systemd-pcrlock for the other PCRs.
This new field allows specification of an fd on which the password
prompt logic will look for POLLHUP events for, and if seen will abort
the query.
The usecase for this is that when we query for a pw on behalf of a
Varlink client we can abort the query automatically if the client dies.
Michael Vogt
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Dan McGregor
Vitaly Kuznetsov
cyclopentane
Mike Yuan
Antonio Alvarez Feijoo
Yu Watanabe
Daan De Meyer
Martin Hundebøll
Lennart Poettering
Luca Boccassi
Aaron Rogers