pam: use /proc/self/sessionid only if CAP_AUDIT_CONTROL is set

diff --git a/src/pam-module.c b/src/pam-module.c
index b4130bbdd6e3e814ff9f6504cfb54073bfbb6206..93eb92956987709681f36b562da6257508527986 100644 (file)
--- a/src/pam-module.c
+++ b/src/pam-module.c
@@ -221,18 +221,19 @@ static uint64_t get_session_id(int *mode) {
 
         /* First attempt: let's use the session ID of the audit
          * system, if it is available. */
-        if (read_one_line_file("/proc/self/sessionid", &s) >= 0) {
-                uint32_t u;
-                int r;
+        if (have_effective_cap(CAP_AUDIT_CONTROL) > 0)
+                if (read_one_line_file("/proc/self/sessionid", &s) >= 0) {
+                        uint32_t u;
+                        int r;
 
-                r = safe_atou32(s, &u);
-                free(s);
+                        r = safe_atou32(s, &u);
+                        free(s);
 
-                if (r >= 0 && u != (uint32_t) -1 && u > 0) {
-                        *mode = SESSION_ID_AUDIT;
-                        return (uint64_t) u;
+                        if (r >= 0 && u != (uint32_t) -1 && u > 0) {
+                                *mode = SESSION_ID_AUDIT;
+                                return (uint64_t) u;
+                        }
                 }
-        }
 
         /* Second attempt, use our own counter. */
         if ((fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-session")) >= 0) {
@@ -289,7 +290,7 @@ static int get_user_data(
         assert(ret_username);
         assert(ret_pw);
 
-        if (have_effective_cap(CAP_AUDIT_CONTROL)) {
+        if (have_effective_cap(CAP_AUDIT_CONTROL) > 0) {
                 /* Only use audit login uid if we are executed with
                  * sufficient capabilities so that pam_loginuid could
                  * do its job. If we are lacking the CAP_AUDIT_CONTROL