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From:   Len Baker <len.baker@gmx.com>
To:     Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc:     Len Baker <len.baker@gmx.com>, Nicolas Pitre <npitre@baylibre.com>,
        Boris Brezillon <boris.brezillon@collabora.com>,
        Kees Cook <keescook@chromium.org>,
        linux-i3c@lists.infradead.org, linux-hardening@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] i3c/master/mipi-i3c-hci: Prefer kcalloc over open coded arithmetic
Date:   Sun, 12 Sep 2021 17:51:35 +0200
Message-Id: <20210912155135.7541-1-len.baker@gmx.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
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As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

So, use the purpose specific kcalloc() function instead of the argument
size * count in the kzalloc() function.

[1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-cod=
ed-arithmetic-in-allocator-arguments

Signed-off-by: Len Baker <len.baker@gmx.com>
=2D--
 drivers/i3c/master/mipi-i3c-hci/hci.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mi=
pi-i3c-hci/hci.h
index 80beb1d5be8f..f109923f6c3f 100644
=2D-- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -98,7 +98,7 @@ struct hci_xfer {

 static inline struct hci_xfer *hci_alloc_xfer(unsigned int n)
 {
-	return kzalloc(sizeof(struct hci_xfer) * n, GFP_KERNEL);
+	return kcalloc(n, sizeof(struct hci_xfer), GFP_KERNEL);
 }

 static inline void hci_free_xfer(struct hci_xfer *xfer, unsigned int n)
=2D-
2.25.1