Received-SPF: pass (google.com: domain of linux-kernel+bounces-186738-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: Armin Wolf <W_Armin@gmx.de>
To: rafael@kernel.org,
	lenb@kernel.org
Cc: linux-acpi@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] ACPI: EC: Abort address space access upon error
Date: Wed, 22 May 2024 23:36:48 +0200
Message-Id: <20240522213649.2860-1-W_Armin@gmx.de>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
UI-OutboundReport: notjunk:1;M01:P0:wGvHOcVoVow=;xXrCdUGZuv91I14nLlAQifWtP+w
 ZuEdifo5kzPJCMoCiS4eoG1spfsbiUewYx1BHG0ueqwBhgQwaKifBWn7ehpfAz7yglB7IgooY
 vsb0kaQlfioOaOa7ZHtk4Hj0ZE2jVNoTLZEKqOdx8H9GBWwlRC4IBSdncGt1sqytIdUId9UPT
 Fk4S09TIN1dFSAh+K0HK1e7PVNbvUBf91uRrKi/jQhzr72kdwRUbiCYphAFDSICTfg1uL+bRR
 D+7PkF4hTyiqsrBeB9YMZTkRBZDVNMXVZVni70OsU83FGwdx3A4F3iJstppWX7OypD2EbfOqP
 Zpv2j2rMM7fmcphmkiQVUX7HhEVhx2YrzPk6YNP1DLIPkVUxdaLPDX3fXtHLl+bWAyEQG9OWI
 qDOlUcLgUB4ssl1pI9bHmkF/Um+zuThOER+oIWnSewXeXTKfnVT9opRPtxV1fHAYACuEvY9Xv
 +ysiFLnCyYUf3bh3QNqvT+5A7UTAQZyJct35P22ZmDZ1Y4Icyq63vOll9gfMjx+aAE9ZSyZp1
 w/b3j0TnZSMk+C/P7+casGZJuUHw8ZIJ7xFk9oFgqN+Ah4aOBuTjSSjghab1T4wI45SpYePuh
 sNBtvksyPGCtOPiWSWgCuCvDOhbyc2XTr1q1bdxV5EaUq9Bl8EuNJbxc1kTC76RnM6FdFqXva
 MvpAj+Vskn5NXJMmevUFQrPWqZ6IiQVADcQSArwYyhRApV9P7PjI9Cotzkua7EbZDON9l1DMu
 iEaOf1xy4/J7Qn5OOwyi3sGiELukY+7h2NOGvca1WWQpZy0XMUfNkQvPKzAYUWXvJxVyIi97v
 6EUmCMH5C+LOKPPXXZYP/atnCjHwpzEdSr+ovD/BbTbZg=

Then a multi-byte address space access is requested, acpi_ec_read()/
acpi_ec_write() is being called multiple times.

Abort such operations if a single call to acpi_ec_read()/
acpi_ec_write() fails, as the data read from/written to the EC
might be incomplete.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
=2D--
 drivers/acpi/ec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index e7793ee9e649..a68dce2147a4 100644
=2D-- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1333,10 +1333,13 @@ acpi_ec_space_handler(u32 function, acpi_physical_=
address address,
 	if (ec->busy_polling || bits > 8)
 		acpi_ec_burst_enable(ec);

-	for (i =3D 0; i < bytes; ++i, ++address, ++value)
+	for (i =3D 0; i < bytes; ++i, ++address, ++value) {
 		result =3D (function =3D=3D ACPI_READ) ?
 			acpi_ec_read(ec, address, value) :
 			acpi_ec_write(ec, address, *value);
+		if (result < 0)
+			break;
+	}

 	if (ec->busy_polling || bits > 8)
 		acpi_ec_burst_disable(ec);
=2D-
2.39.2