linux-kernel - [PATCH] regulator: fix pointer table overallocation

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Message-Id: <407fbd06a02caf038a9ba3baa51c7d6d47cd6517.1597000795.git.mirq-linux@rere.qmqm.pl>
Date:   Sun, 09 Aug 2020 21:21:16 +0200
From:   Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:     Dmitry Osipenko <digetx@...il.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH] regulator: fix pointer table overallocation

The code allocates sizeof(regulator_dev) for a pointer. Make it less
generous. Let kcalloc() calculate the size, while at it.

Cc: stable@...r.kernel.org
Fixes: d8ca7d184b33 ("regulator: core: Introduce API for regulators coupling customization")
Signed-off-by: Michał Mirosław <mirq-linux@...e.qmqm.pl>
---
 drivers/regulator/core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 75ff7c563c5d..9e18997777d3 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5011,20 +5011,20 @@ static void regulator_remove_coupling(struct regulator_dev *rdev)
 
 static int regulator_init_coupling(struct regulator_dev *rdev)
 {
+	struct regulator_dev **coupled;
 	int err, n_phandles;
-	size_t alloc_size;
 
 	if (!IS_ENABLED(CONFIG_OF))
 		n_phandles = 0;
 	else
 		n_phandles = of_get_n_coupled(rdev);
 
-	alloc_size = sizeof(*rdev) * (n_phandles + 1);
-
-	rdev->coupling_desc.coupled_rdevs = kzalloc(alloc_size, GFP_KERNEL);
-	if (!rdev->coupling_desc.coupled_rdevs)
+	coupled = kcalloc(n_phandles + 1, sizeof(*coupled), GFP_KERNEL);
+	if (!coupled)
 		return -ENOMEM;
 
+	rdev->coupling_desc.coupled_rdevs = coupled;
+
 	/*
 	 * Every regulator should always have coupling descriptor filled with
 	 * at least pointer to itself.
-- 
2.20.1