nss: only read logging config from environment variables

keszybz · keszybz · commit a7d15a246597 · 2022-01-11T13:39:52.000+01:00
log_parse_environment() uses should_parse_proc_cmdline() to determine whether it should parse settings from the kernel command line. But the checks that should_parse_proc_cmdline() apply to the whole process, and we could get a positive answer also when log_parse_environment() was called from one of the nss modules. In case of nss-modules, we don't want to look at the kernel command line. log_parse_environment_variables() that only looks at the environment variables is split out and used in the nss modules. Fixes systemd#22020.
diff --git a/src/basic/log.c b/src/basic/log.c
@@ -1189,14 +1189,9 @@ static bool should_parse_proc_cmdline(void) {
         return getpid_cached() == p;
 }
 
-void log_parse_environment(void) {
+void log_parse_environment_variables(void) {
         const char *e;
 
-        /* Do not call from library code. */
-
-        if (should_parse_proc_cmdline())
-                (void) proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
-
         e = getenv("SYSTEMD_LOG_TARGET");
         if (e && log_set_target_from_string(e) < 0)
                 log_warning("Failed to parse log target '%s'. Ignoring.", e);
@@ -1222,6 +1217,15 @@ void log_parse_environment(void) {
                 log_warning("Failed to parse log tid '%s'. Ignoring.", e);
 }
 
+void log_parse_environment(void) {
+        /* Do not call from library code. */
+
+        if (should_parse_proc_cmdline())
+                (void) proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
+
+        log_parse_environment_variables();
+}
+
 LogTarget log_get_target(void) {
         return log_target;
 }
diff --git a/src/basic/log.h b/src/basic/log.h
@@ -82,6 +82,7 @@ int log_open(void);
 void log_close(void);
 void log_forget_fds(void);
 
+void log_parse_environment_variables(void);
 void log_parse_environment(void);
 
 int log_dispatch_internal(
diff --git a/src/nss-mymachines/nss-mymachines.c b/src/nss-mymachines/nss-mymachines.c
@@ -24,7 +24,7 @@
 
 static void setup_logging_once(void) {
         static pthread_once_t once = PTHREAD_ONCE_INIT;
-        assert_se(pthread_once(&once, log_parse_environment) == 0);
+        assert_se(pthread_once(&once, log_parse_environment_variables) == 0);
 }
 
 #define NSS_ENTRYPOINT_BEGIN                    \
diff --git a/src/nss-resolve/nss-resolve.c b/src/nss-resolve/nss-resolve.c
@@ -22,7 +22,7 @@
 static JsonDispatchFlags json_dispatch_flags = 0;
 
 static void setup_logging(void) {
-        log_parse_environment();
+        log_parse_environment_variables();
 
         if (DEBUG_LOGGING)
                 json_dispatch_flags = JSON_LOG;
diff --git a/src/nss-systemd/nss-systemd.c b/src/nss-systemd/nss-systemd.c
@@ -118,7 +118,7 @@ static GetentData getsgent_data = {
 
 static void setup_logging_once(void) {
         static pthread_once_t once = PTHREAD_ONCE_INIT;
-        assert_se(pthread_once(&once, log_parse_environment) == 0);
+        assert_se(pthread_once(&once, log_parse_environment_variables) == 0);
 }
 
 #define NSS_ENTRYPOINT_BEGIN                    \

Original file line number	Diff line number	Diff line change
`@@ -24,7 +24,7 @@`
`24`	`24`
`25`	`25`	`static void setup_logging_once(void) {`
`26`	`26`	`static pthread_once_t once = PTHREAD_ONCE_INIT;`
`27`		`- assert_se(pthread_once(&once, log_parse_environment) == 0);`
	`27`	`+ assert_se(pthread_once(&once, log_parse_environment_variables) == 0);`
`28`	`28`	`}`
`29`	`29`
`30`	`30`	`#define NSS_ENTRYPOINT_BEGIN \`
Original file line number	Diff line number	Diff line change
`@@ -118,7 +118,7 @@ static GetentData getsgent_data = {`
`118`	`118`
`119`	`119`	`static void setup_logging_once(void) {`
`120`	`120`	`static pthread_once_t once = PTHREAD_ONCE_INIT;`
`121`		`- assert_se(pthread_once(&once, log_parse_environment) == 0);`
	`121`	`+ assert_se(pthread_once(&once, log_parse_environment_variables) == 0);`
`122`	`122`	`}`
`123`	`123`
`124`	`124`	`#define NSS_ENTRYPOINT_BEGIN \`