From 338a5cecf0f839331f0a58bff8aaae79e134799e Mon Sep 17 00:00:00 2001
From: Fred Oh <fred@codeaurora.org>
Date: Tue, 07 Apr 2015 19:22:29 -0700
Subject: [PATCH] ASoC: msm: qdsp6v2: validate audio client in callback

In case of single stream multiple device(SSMD) use-case audio session is
freed on first EOS. There are some chance to crash when 2nd EOS event is
reached with some delay. This make sure return properly if audio client
is not valid.

Bug: 36252027
Change-Id: I3711d8e039fc37e654ca5230f3dc8784c6dba071
Signed-off-by: Fred Oh <fred@codeaurora.org>
Signed-off-by: Siqi Lin <siqilin@google.com>
---

diff --git a/sound/soc/msm/qdsp6v2/q6asm.c b/sound/soc/msm/qdsp6v2/q6asm.c
index b17a440..4f486b1 100644
--- a/sound/soc/msm/qdsp6v2/q6asm.c
+++ b/sound/soc/msm/qdsp6v2/q6asm.c
@@ -329,6 +329,16 @@
 	return -ENOMEM;
 }
 
+static bool q6asm_is_valid_audio_client(struct audio_client *ac)
+{
+	int n;
+	for (n = 1; n <= SESSION_MAX; n++) {
+		if (session[n] == ac)
+			return 1;
+	}
+	return 0;
+}
+
 static void q6asm_session_free(struct audio_client *ac)
 {
 	pr_debug("%s: sessionid[%d]\n", __func__, ac->session);
@@ -905,7 +915,8 @@
 		pr_err("ac or priv NULL\n");
 		return -EINVAL;
 	}
-	if (ac->session <= 0 || ac->session > 8) {
+	if (ac->session <= 0 || ac->session > 8 ||
+		!q6asm_is_valid_audio_client(ac)) {
 		pr_err("%s:Session ID is invalid, session = %d\n", __func__,
 			ac->session);
 		return -EINVAL;