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From: Erick Archer <erick.archer@gmx.com>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
	Jeffrey Hugo <quic_jhugo@quicinc.com>,
	Erick Archer <erick.archer@gmx.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Dan Carpenter <error27@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-arm-msm@vger.kernel.org,
	mhi@lists.linux.dev,
	linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: [PATCH] bus: mhi: ep: Use kcalloc() instead of kzalloc()
Date: Sat, 20 Jan 2024 16:25:18 +0100
Message-Id: <20240120152518.13006-1-erick.archer@gmx.com>
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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
count * size in the kzalloc() function.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-co=
ded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/162
Signed-off-by: Erick Archer <erick.archer@gmx.com>
=2D--
 drivers/bus/mhi/ep/main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 65fc1d738bec..8d7a4102bdb7 100644
=2D-- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1149,8 +1149,9 @@ int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl)
 	mhi_ep_mmio_mask_interrupts(mhi_cntrl);
 	mhi_ep_mmio_init(mhi_cntrl);

-	mhi_cntrl->mhi_event =3D kzalloc(mhi_cntrl->event_rings * (sizeof(*mhi_c=
ntrl->mhi_event)),
-					GFP_KERNEL);
+	mhi_cntrl->mhi_event =3D kcalloc(mhi_cntrl->event_rings,
+				       sizeof(*mhi_cntrl->mhi_event),
+				       GFP_KERNEL);
 	if (!mhi_cntrl->mhi_event)
 		return -ENOMEM;

=2D-
2.25.1