Patch "ACPI: ioapic: Clear on-stack resource before using it" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

ACPI: ioapic: Clear on-stack resource before using it

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
acpi-ioapic-clear-on-stack-resource-before-using-it.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Joerg Roedel <[email protected]>
Date: Wed, 22 Mar 2017 18:33:23 +0100
Subject: ACPI: ioapic: Clear on-stack resource before using it

From: Joerg Roedel <[email protected]>

commit e3d5092b6756b9e0b08f94bbeafcc7afe19f0996 upstream.

The on-stack resource-window 'win' in setup_res() is not properly initialized. This causes the pointers in the embedded 'struct resource' to contain stale addresses.

These pointers (in my case the ->child pointer) later get propagated to the global iomem_resources list, causing a #GP exception when the list is traversed in iomem_map_sanity_check().

---
 drivers/acpi/ioapic.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -45,6 +45,12 @@ static acpi_status setup_res(struct acpi
 	struct resource *res = data;
 	struct resource_win win;
 
+	/*
+	 * We might assign this to 'res' later, make sure all pointers are
+	 * cleared before the resource is added to the global list
+	 */
+	memset(&win, 0, sizeof(win));
+
 	res->flags = 0;
 	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
 		return AE_OK;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/acpi-ioapic-clear-on-stack-resource-before-using-it.patch