From f8e6f4aaedf8c96bf909e027631f4910ac9c4539 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Thu, 22 Feb 2018 23:55:14 +0100 Subject: [PATCH] basic/log: make sure header is printed correctly, add test If log_do_header() was called with overly long parameters, it'd generate improper output. Essentially, it'd be truncated at random point, in particular missing a newline at the end, so it'd run with the next field, usually MESSAGE=. log_do_header is called with parameters from compiled code (file name, lien nubmer, etc), so in practice this was unlikely to ever be a problem, but it is possible. In particular, if systemd was compiled from sources in some deeply nested directory (which happens for example in mock and other build roots), the filename could be very long. As a safety measure, let's truncate all parameters to 256 bytes. So we have 5 fields which are 256 bytes (plus the field name prefix), and a few other fields with fixed width. This must always fit in the 2048 byte buffer. I don't think there's much gain in calculating the required length precisely, since it's a lot of fields and a few bytes allocated on the stack don't matter. --- src/basic/log.c | 64 +++++++++++++++++++++++++++-------------------------- src/test/test-log.c | 39 ++++++++++++++++++++++++++------ 2 files changed, 65 insertions(+), 38 deletions(-) diff --git a/src/basic/log.c b/src/basic/log.c index 85f8eea..19c4ec7 100644 --- a/src/basic/log.c +++ b/src/basic/log.c @@ -498,38 +498,40 @@ static int log_do_header( const char *file, int line, const char *func, const char *object_field, const char *object, const char *extra_field, const char *extra) { + int r; - snprintf(header, size, - "PRIORITY=%i\n" - "SYSLOG_FACILITY=%i\n" - "%s%s%s" - "%s%.*i%s" - "%s%s%s" - "%s%.*i%s" - "%s%s%s" - "%s%s%s" - "SYSLOG_IDENTIFIER=%s\n", - LOG_PRI(level), - LOG_FAC(level), - isempty(file) ? "" : "CODE_FILE=", - isempty(file) ? "" : file, - isempty(file) ? "" : "\n", - line ? "CODE_LINE=" : "", - line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */ - line ? "\n" : "", - isempty(func) ? "" : "CODE_FUNC=", - isempty(func) ? "" : func, - isempty(func) ? "" : "\n", - error ? "ERRNO=" : "", - error ? 1 : 0, error, - error ? "\n" : "", - isempty(object) ? "" : object_field, - isempty(object) ? "" : object, - isempty(object) ? "" : "\n", - isempty(extra) ? "" : extra_field, - isempty(extra) ? "" : extra, - isempty(extra) ? "" : "\n", - program_invocation_short_name); + r = snprintf(header, size, + "PRIORITY=%i\n" + "SYSLOG_FACILITY=%i\n" + "%s%.256s%s" /* CODE_FILE */ + "%s%.*i%s" /* CODE_LINE */ + "%s%.256s%s" /* CODE_FUNC */ + "%s%.*i%s" /* ERRNO */ + "%s%.256s%s" /* object */ + "%s%.256s%s" /* extra */ + "SYSLOG_IDENTIFIER=%.256s\n", + LOG_PRI(level), + LOG_FAC(level), + isempty(file) ? "" : "CODE_FILE=", + isempty(file) ? "" : file, + isempty(file) ? "" : "\n", + line ? "CODE_LINE=" : "", + line ? 1 : 0, line, /* %.0d means no output too, special case for 0 */ + line ? "\n" : "", + isempty(func) ? "" : "CODE_FUNC=", + isempty(func) ? "" : func, + isempty(func) ? "" : "\n", + error ? "ERRNO=" : "", + error ? 1 : 0, error, + error ? "\n" : "", + isempty(object) ? "" : object_field, + isempty(object) ? "" : object, + isempty(object) ? "" : "\n", + isempty(extra) ? "" : extra_field, + isempty(extra) ? "" : extra, + isempty(extra) ? "" : "\n", + program_invocation_short_name); + assert((size_t) r < size); return 0; } diff --git a/src/test/test-log.c b/src/test/test-log.c index fd19899..4a3c895 100644 --- a/src/test/test-log.c +++ b/src/test/test-log.c @@ -35,19 +35,18 @@ assert_cc((LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, LOG_LOCAL3 | LOG_DEBUG) & LOG assert_cc((LOG_REALM_PLUS_LEVEL(LOG_REALM_UDEV, LOG_USER | LOG_INFO) & LOG_PRIMASK) == LOG_INFO); -int main(int argc, char* argv[]) { - - log_set_target(LOG_TARGET_CONSOLE); - log_open(); +#define X10(x) x x x x x x x x x x +#define X100(x) X10(X10(x)) +#define X1000(x) X100(X10(x)) +static void test_log_console(void) { log_struct(LOG_INFO, "MESSAGE=Waldo PID="PID_FMT, getpid_cached(), "SERVICE=piepapo", NULL); +} - log_set_target(LOG_TARGET_JOURNAL); - log_open(); - +static void test_log_journal(void) { log_struct(LOG_INFO, "MESSAGE=Foobar PID="PID_FMT, getpid_cached(), "SERVICE=foobar", @@ -59,6 +58,32 @@ int main(int argc, char* argv[]) { (int) 1, 'A', (short) 2, (long int) 3, (long long int) 4, (void*) 1, "foo", (float) 2.5f, (double) 3.5, (long double) 4.5, "SUFFIX=GOT IT", NULL); +} + +static void test_long_lines(void) { + log_object_internal(LOG_NOTICE, + EUCLEAN, + X1000("abcd_") ".txt", + 1000000, + X1000("fff") "unc", + "OBJECT=", + X1000("obj_") "ect", + "EXTRA=", + X1000("ext_") "tra", + "asdfasdf %s asdfasdfa", "foobar"); +} + +int main(int argc, char* argv[]) { + int target; + + for (target = 0; target < _LOG_TARGET_MAX; target++) { + log_set_target(target); + log_open(); + + test_log_console(); + test_log_journal(); + test_long_lines(); + } return 0; } -- 2.7.4