Units are copied out via sendmsg datafd from images, but that means
the SELinux labels get lost in transit. Extract them and copy them over.
Given recvmsg cannot use multiple IOV transparently when the sizes are
variable, use a '\0' as a separator between the filename and the label.
Compared to PID1 where systemd-oomd has to be the client to PID1
because PID1 is a more privileged process than systemd-oomd, systemd-oomd
is the more privileged process compared to a user manager so we have
user managers be the client whereas systemd-oomd is now the server.
The same varlink protocol is used between user managers and systemd-oomd
to deliver ManagedOOM property updates. systemd-oomd now sets up a varlink
server that user managers connect to to send ManagedOOM property updates.
We also add extra validation to make sure that non-root senders don't
send updates for cgroups they don't own.
The integration test was extended to repeat the chill/bloat test using
a user manager instead of PID1.
Unfortunately, when checking the return/exit code using &&, ||, if,
while, etc., `set -e` is disabled for all nested functions as well,
which leads to incorrectly ignored errors, *sigh*.
Example:
```
set -eu
set -o pipefail
task() {
echo "task init"
echo "this should fail"
false
nonexistentcommand
echo "task end (we shouldn't be here)"
}
if ! task; then
echo >&2 "The task failed"
exit 1
else
echo "The task passed"
fi
```
```
$ bash test.sh
task init
this should fail
test.sh: line 10: nonexistentcommand: command not found
task end (we shouldn't be here)
The task passed
$ echo $?
0
```
But without the `if`, everything works "as expected":
```
set -eu
set -o pipefail
task() {
echo "task init"
echo "this should fail"
false
nonexistentcommand
echo "task end (we shouldn't be here)"
}
task
```
```
$ bash test.sh
task init
this should fail
$ echo $?
1
```
Wonderful.
to suppress OpenSSL 3.0 deprecation warnings (until a proper solution
is deployed):
```
../src/shared/creds-util.c: In function ‘sha256_hash_host_and_tpm2_key’:
../src/shared/creds-util.c:412:9: error: ‘SHA256_Init’ is deprecated: Since OpenSSL 3.0 [-Werror=deprecated-declarations]
412 | if (SHA256_Init(&sha256_context) != 1)
| ^~
In file included from /usr/include/openssl/x509.h:41,
from ../src/shared/openssl-util.h:8,
from ../src/shared/creds-util.c:21:
/usr/include/openssl/sha.h:73:27: note: declared here
73 | OSSL_DEPRECATEDIN_3_0 int SHA256_Init(SHA256_CTX *c);
| ^~~~~~~~~~~
../src/shared/creds-util.c:415:9: error: ‘SHA256_Update’ is deprecated: Since OpenSSL 3.0 [-Werror=deprecated-declarations]
415 | if (host_key && SHA256_Update(&sha256_context, host_key, host_key_size) != 1)
| ^~
In file included from /usr/include/openssl/x509.h:41,
from ../src/shared/openssl-util.h:8,
from ../src/shared/creds-util.c:21:
/usr/include/openssl/sha.h:74:27: note: declared here
74 | OSSL_DEPRECATEDIN_3_0 int SHA256_Update(SHA256_CTX *c,
| ^~~~~~~~~~~~~
../src/shared/creds-util.c:418:9: error: ‘SHA256_Update’ is deprecated: Since OpenSSL 3.0 [-Werror=deprecated-declarations]
418 | if (tpm2_key && SHA256_Update(&sha256_context, tpm2_key, tpm2_key_size) != 1)
| ^~
In file included from /usr/include/openssl/x509.h:41,
from ../src/shared/openssl-util.h:8,
from ../src/shared/creds-util.c:21:
/usr/include/openssl/sha.h:74:27: note: declared here
74 | OSSL_DEPRECATEDIN_3_0 int SHA256_Update(SHA256_CTX *c,
| ^~~~~~~~~~~~~
../src/shared/creds-util.c:421:9: error: ‘SHA256_Final’ is deprecated: Since OpenSSL 3.0 [-Werror=deprecated-declarations]
421 | if (SHA256_Final(ret, &sha256_context) != 1)
| ^~
In file included from /usr/include/openssl/x509.h:41,
from ../src/shared/openssl-util.h:8,
from ../src/shared/creds-util.c:21:
/usr/include/openssl/sha.h:76:27: note: declared here
76 | OSSL_DEPRECATEDIN_3_0 int SHA256_Final(unsigned char *md, SHA256_CTX *c);
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors
```
Gets rid of a few gotos, allows removing the extra ret variable and
will also be used in a future commit by the codepath that receives
cgroups from user instances of systemd.
i.e. let's pick some files we know are too large, or where struct stat's
.st_size is zero even though non-empty, and test read_virtual_file()
with that, to ensure things are handled sensibly. Goal is to ensure all
three major codepaths in read_virtual_file() are tested.
Prompted-by: #20743
We mishandled the case where the size we read from the file actually
matched the maximum size fully. In that case we cannot really make a
determination whether the file was fully read or only partially. In that
case let's do another loop, so that we operate with a buffer, and
we can detect the EOF (which will be signalled to us via a short read).
There's a very gradual increase of anonymous memory in systemd-journald that
blames to 2ac67221bb.
systemd-journald makes many calls to read /proc/PID/cmdline and
/proc/PID/status, both of which tend to be well under 4K. However the
combination of allocating 4M read buffers, then using `realloc()` to
shrink the buffer in `read_virtual_file()` appears to be creating
fragmentation in the heap (when combined with the other allocations
systemd-journald is doing).
To help mitigate this, try reading /proc with a 4K buffer as
`read_virtual_file()` did before 2ac67221bb.
If it isn't big enough then try again with the larger buffers.
Lennart Poettering
Michal Sekletar
Luca Boccassi
Daan De Meyer
Lukas Senionis
Frantisek Sumsal
Lia Lenckowski
Hugo Carvalho
Christian Wehrli
Piotr Drąg
Yu Watanabe
Anita Zhang