diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index baf855e596c2..05724277c2a9 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -333,7 +333,12 @@ struct machine *machines__findnew(struct machines *machines, pid_t pid)
 	if ((pid != HOST_KERNEL_ID) &&
 	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
 	    (symbol_conf.guestmount)) {
-		snprintf(path, sizeof(path), "%s/%d", symbol_conf.guestmount, pid);
+		if (snprintf(path, sizeof(path), "%s/%d",
+			     symbol_conf.guestmount, pid) >= (int)sizeof(path)) {
+			pr_err("Guest path too long for pid %d\n", pid);
+			machine = NULL;
+			goto out;
+		}
 		if (access(path, R_OK)) {
 			static struct strlist *seen;