From 2505a210fc126599013aec2be741df20aaacc490 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 8 May 2020 16:40:22 +0200
Subject: [PATCH] media: firewire: Using uninitialized values in node_probe()
Git-commit: 2505a210fc126599013aec2be741df20aaacc490
Patch-mainline: v5.9-rc1
References: git-fixes

If fw_csr_string() returns -ENOENT, then "name" is uninitialized.  So
then the "strlen(model_names[i]) <= name_len" is true because strlen()
is unsigned and -ENOENT is type promoted to a very high positive value.
Then the "strncmp(name, model_names[i], name_len)" uses uninitialized
data because "name" is uninitialized.

Fixes: 92374e886c75 ("[media] firedtv: drop obsolete backend abstraction")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/firewire/firedtv-fw.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/firewire/firedtv-fw.c b/drivers/media/firewire/firedtv-fw.c
index 97144734eb05..3f1ca40b9b98 100644
--- a/drivers/media/firewire/firedtv-fw.c
+++ b/drivers/media/firewire/firedtv-fw.c
@@ -272,6 +272,8 @@ static int node_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 
 	name_len = fw_csr_string(unit->directory, CSR_MODEL,
 				 name, sizeof(name));
+	if (name_len < 0)
+		return name_len;
 	for (i = ARRAY_SIZE(model_names); --i; )
 		if (strlen(model_names[i]) <= name_len &&
 		    strncmp(name, model_names[i], name_len) == 0)
-- 
2.16.4