Re: [PATCH] ACPI/IORT: Fix iort_get_platform_device_domain() uninitialized pointer value

From: Will Deacon <will.deacon@arm.com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Patrick Bellasi <patrick.bellasi@arm.com>,
	linux-acpi@vger.kernel.org, Hanjun Guo <hanjun.guo@linaro.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ACPI/IORT: Fix iort_get_platform_device_domain() uninitialized pointer value
Date: Fri, 30 Nov 2018 13:21:03 +0000	[thread overview]
Message-ID: <20181130132102.GC9000@arm.com> (raw)
In-Reply-To: <20181129095559.26007-1-lorenzo.pieralisi@arm.com>

On Thu, Nov 29, 2018 at 09:55:59AM +0000, Lorenzo Pieralisi wrote:
> Running the Clang static analyzer on IORT code detected the following
> error:
> 
> Logic error: Branch condition evaluates to a garbage value
> 
> in
> 
> iort_get_platform_device_domain()
> 
> If the named component associated with a given device has no IORT
> mappings, iort_get_platform_device_domain() exits its MSI mapping loop
> with msi_parent pointer containing garbage, which can lead to erroneous
> code path execution.
> 
> Initialize the msi_parent pointer, fixing the bug.
> 
> Fixes: d4f54a186667 ("ACPI: platform: setup MSI domain for ACPI based
> platform device")
> Reported-by: Patrick Bellasi <patrick.bellasi@arm.com>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
>  drivers/acpi/arm64/iort.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: Will Deacon <will.deacon@arm.com>

Looks like one for 4.20.

Will

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 2a361e22d38d..70f4e80b9246 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -700,7 +700,7 @@ static void iort_set_device_domain(struct device *dev,
>   */
>  static struct irq_domain *iort_get_platform_device_domain(struct device *dev)
>  {
> -	struct acpi_iort_node *node, *msi_parent;
> +	struct acpi_iort_node *node, *msi_parent = NULL;
>  	struct fwnode_handle *iort_fwnode;
>  	struct acpi_iort_its_group *its;
>  	int i;
> -- 
> 2.19.2
> 