If a journal file contains a truncated ZSTD frame (i.e. a frame with
Frame_Content_Size > 0, but with not enough data in Data_Block),
ZSTD_decompressStream() would return a non-zero, non-error value. This
would then skip the error path in the ZSTD_isError() branch and we'd hit
the following assert:
$ build-local/journalctl -o cat --file zstd-truncated.journal
Assertion 'output.pos >= prefix_len + 1' failed at src/basic/compress.c:1236, function decompress_startswith_zstd(). Aborting.
Aborted (core dumped) build-local/journalctl -o cat --file zstd-truncated.journal
Let's handle this situation gracefully and return EBADMSG instead.
Also, add another journalctl invocation to the corrupted-journals test
that goes through the sd_journal_get_data() -> decompress_startswith_zstd()
code path which, among other things, covers the issue when run on the
provided journal file.
Last month I monkey-patched journald to produce a small (64K) but valid
journal and used that as an input to four AFL fuzzers. After a month it
generated quite a nice corpora (4738 test cases) and after filtering
and minimizing it I was left with 619 unique journals with various
levels of corruption that probe the journal code.
It seems to detect past issues like systemd#26567, etc.
This adds a test for checking we can safely order boot IDs via the
timestamp of their most recent known entry. It takes a set of journal
files (supplied by a user) and that are partially corrupted, and ensures
we get a clear, defined order of boot IDs out of it.
Frantisek Sumsal
Lennart Poettering