diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 71d6629e65c9..da13683d52d1 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -839,6 +839,12 @@ static void decode_data(struct sixpack *sp, unsigned char inbyte)
 		return;
 	}
 
+	if (sp->rx_count_cooked + 2 >= sizeof(sp->cooked_buf)) {
+		pr_err("6pack: cooked buffer overrun, data loss\n");
+		sp->rx_count = 0;
+		return;
+	}
+
 	buf = sp->raw_buf;
 	sp->cooked_buf[sp->rx_count_cooked++] =
 		buf[0] | ((buf[1] << 2) & 0xc0);