Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Patrick Rudolph <patrick.rudolph@9elements.com>,
        Mark Brown <broonie@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 429/530] regulator: core: Prevent integer underflow
Date:   Mon, 24 Oct 2022 13:32:53 +0200
Message-Id: <20221024113104.508396489@linuxfoundation.org>
In-Reply-To: <20221024113044.976326639@linuxfoundation.org>
References: <20221024113044.976326639@linuxfoundation.org>
User-Agent: quilt/0.67
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Patrick Rudolph <patrick.rudolph@9elements.com>

[ Upstream commit 8d8e16592022c9650df8aedfe6552ed478d7135b ]

By using a ratio of delay to poll_enabled_time that is not integer
time_remaining underflows and does not exit the loop as expected.
As delay could be derived from DT and poll_enabled_time is defined
in the driver this can easily happen.

Use a signed iterator to make sure that the loop exits once
the remaining time is negative.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Link: https://lore.kernel.org/r/20220909125954.577669-1-patrick.rudolph@9elements.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/regulator/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 43613db7af75..aa4d78b02483 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2636,7 +2636,7 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 	 * expired, return -ETIMEDOUT.
 	 */
 	if (rdev->desc->poll_enabled_time) {
-		unsigned int time_remaining = delay;
+		int time_remaining = delay;
 
 		while (time_remaining > 0) {
 			_regulator_enable_delay(rdev->desc->poll_enabled_time);
-- 
2.35.1