From: Dmitry Osipenko <digetx@gmail.com>
Date: Sun, 23 Jun 2019 17:50:53 +0000 (+0300)
Subject: opp: Don't use IS_ERR on invalid supplies
X-Git-Tag: v5.1.20~95
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44c92c0c7407b150f50af0c063ddb54c91df3c84;p=thirdparty%2Fkernel%2Fstable.git

opp: Don't use IS_ERR on invalid supplies

commit 560d1bcad715c215e7ffe5d7cffe045974b623d0 upstream.

_set_opp_custom() receives a set of OPP supplies as its arguments and
the caller of it passes NULL when the supplies are not valid. But
_set_opp_custom(), by mistake, checks for error by performing
IS_ERR(old_supply) on it which will always evaluate to false.

The problem was spotted during of testing of upcoming update for the
NVIDIA Tegra CPUFreq driver.

Cc: stable <stable@vger.kernel.org>
Fixes: 7e535993fa4f ("OPP: Separate out custom OPP handler specific code")
Reported-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[ Viresh: Massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 0420f7e8ad5b0..f5d565804e52d 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -631,7 +631,7 @@ static int _set_opp_custom(const struct opp_table *opp_table,
 
 	data->old_opp.rate = old_freq;
 	size = sizeof(*old_supply) * opp_table->regulator_count;
-	if (IS_ERR(old_supply))
+	if (!old_supply)
 		memset(data->old_opp.supplies, 0, size);
 	else
 		memcpy(data->old_opp.supplies, old_supply, size);