SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

compress: gracefully handle a truncated ZSTD frame

Browse Source 
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.
This commit is contained in:
Frantisek Sumsal
2026-04-20 09:37:13 +02:00
committed by Daan De Meyer
parent e869c83367
commit 35eb598af2
3 changed files with 5 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/basic/compress.c
+3 -1
View File
@@ -1233,7 +1233,9 @@ static int decompress_startswith_zstd(
log_debug("ZSTD decoder failed: %s", sym_ZSTD_getErrorName(k));
return zstd_ret_to_errno(k);
}
assert(output.pos >= prefix_len + 1);
if (output.pos < prefix_len + 1)
return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "ZSTD decoded less data than indicated, probably corrupted stream.");
return memcmp(*buffer, prefix, prefix_len) == 0 &&
((const uint8_t*) *buffer)[prefix_len] == extra;
test/test-journals/corrupted/zstd-truncated-frame.zst
BIN
View File
Binary file not shown.
test/units/TEST-04-JOURNAL.corrupted-journals.sh
+2
View File
@@ -20,6 +20,7 @@ if [[ "$(systemd-detect-virt -v)" != "qemu" ]]; then
timeout 10 journalctl --file="$file" --boot >/dev/null || [[ $? -lt 124 ]]
timeout 10 journalctl --file="$file" --verify >/dev/null || [[ $? -lt 124 ]]
timeout 10 journalctl --file="$file" --output=export >/dev/null || [[ $? -lt 124 ]]
timeout 10 journalctl --file="$file" --grep=. >/dev/null || [[ $? -lt 124 ]]
timeout 10 journalctl --file="$file" --fields >/dev/null || [[ $? -lt 124 ]]
timeout 10 journalctl --file="$file" --list-boots >/dev/null || [[ $? -lt 124 ]]
if [[ -x /usr/lib/systemd/systemd-journal-remote ]]; then
@@ -36,6 +37,7 @@ fi
timeout 30 journalctl --directory="$JOURNAL_DIR" --boot >/dev/null || [[ $? -lt 124 ]]
timeout 30 journalctl --directory="$JOURNAL_DIR" --verify >/dev/null || [[ $? -lt 124 ]]
timeout 30 journalctl --directory="$JOURNAL_DIR" --output=export >/dev/null || [[ $? -lt 124 ]]
timeout 30 journalctl --directory="$JOURNAL_DIR" --grep=. >/dev/null || [[ $? -lt 124 ]]
timeout 30 journalctl --directory="$JOURNAL_DIR" --fields >/dev/null || [[ $? -lt 124 ]]
timeout 30 journalctl --directory="$JOURNAL_DIR" --list-boots >/dev/null || [[ $? -lt 124 ]]
if [[ -x /usr/lib/systemd/systemd-journal-remote ]]; then