diff --git a/tools/testing/selftests/landlock/audit_test.c b/tools/testing/selftests/landlock/audit_test.c
index 72b5612375dd..4bea8c880a4d 100644
--- a/tools/testing/selftests/landlock/audit_test.c
+++ b/tools/testing/selftests/landlock/audit_test.c
@@ -31,7 +31,7 @@ static int matches_log_signal(struct __test_metadata *const _metadata,
 
 	log_match_len =
 		snprintf(log_match, sizeof(log_match), log_template, opid);
-	if (log_match_len > sizeof(log_match))
+	if (log_match_len >= sizeof(log_match))
 		return -E2BIG;
 
 	return audit_match_record(audit_fd, AUDIT_LANDLOCK_ACCESS, log_match,
diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
index 16afbfdf06bb..50b637354b51 100644
--- a/tools/testing/selftests/landlock/net_test.c
+++ b/tools/testing/selftests/landlock/net_test.c
@@ -2878,7 +2878,7 @@ static int matches_auditlog(const int audit_fd, const char *const blockers,
 		log_match_len = snprintf(log_match, sizeof(log_match),
 					 log_with_addrport_tmpl, blockers,
 					 dir_addr, addr, dir_port, port);
-	if (log_match_len > sizeof(log_match))
+	if (log_match_len >= sizeof(log_match))
 		return -E2BIG;
 
 	return audit_match_record(audit_fd, AUDIT_LANDLOCK_ACCESS, log_match,
@@ -3173,7 +3173,7 @@ static int matches_log_connect_bound(int audit_fd, const char *const blockers,
 
 	log_match_len = snprintf(log_match, sizeof(log_match), log_template,
 				 blockers, addr, lport, addr, dport);
-	if (log_match_len > sizeof(log_match))
+	if (log_match_len >= sizeof(log_match))
 		return -E2BIG;
 
 	return audit_match_record(audit_fd, AUDIT_LANDLOCK_ACCESS, log_match,
diff --git a/tools/testing/selftests/landlock/ptrace_test.c b/tools/testing/selftests/landlock/ptrace_test.c
index 2644445a9d02..e0e7f95e889b 100644
--- a/tools/testing/selftests/landlock/ptrace_test.c
+++ b/tools/testing/selftests/landlock/ptrace_test.c
@@ -305,7 +305,7 @@ static int matches_log_ptrace(struct __test_metadata *const _metadata,
 
 	log_match_len =
 		snprintf(log_match, sizeof(log_match), log_template, opid);
-	if (log_match_len > sizeof(log_match))
+	if (log_match_len >= sizeof(log_match))
 		return -E2BIG;
 
 	return audit_match_record(audit_fd, AUDIT_LANDLOCK_ACCESS, log_match,