diff mbox

[v1] PCI, ACPI: Fix regressions caused by resource_size_t overflow with 32bit kernel

Message ID 1435032732-26160-1-git-send-email-jiang.liu@linux.intel.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Jiang Liu June 23, 2015, 4:12 a.m. UTC 
The data type resource_size_t may be 32 bits or 64 bits depending on
CONFIG_PHYS_ADDR_T_64BIT. So reject ACPI resource descriptors which
will cause resource_size_t overflow with 32bit kernel

This issue was triggered on a platform running 32bit kernel with an
ACPI resource descriptor with address range [0x400000000-0xfffffffff].
Please refer to https://lkml.org/lkml/2015/6/19/277 for more information.

Reported-by: Boszormenyi Zoltan <zboszor@pr.hu>
Fixes: 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation")
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: stable@vger.kernel.org # 4.0
---
 drivers/acpi/resource.c |   24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

Comments

Ingo Molnar June 23, 2015, 7:35 a.m. UTC | #1 
* Jiang Liu <jiang.liu@linux.intel.com> wrote:

> The data type resource_size_t may be 32 bits or 64 bits depending on
> CONFIG_PHYS_ADDR_T_64BIT. So reject ACPI resource descriptors which
> will cause resource_size_t overflow with 32bit kernel
> 
> This issue was triggered on a platform running 32bit kernel with an
> ACPI resource descriptor with address range [0x400000000-0xfffffffff].
> Please refer to https://lkml.org/lkml/2015/6/19/277 for more information.
> 
> Reported-by: Boszormenyi Zoltan <zboszor@pr.hu>
> Fixes: 593669c2ac0f ("x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation")
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> Cc: stable@vger.kernel.org # 4.0

Yeah, so please use the customary changelog style we use in the kernel:

  " Current code does (A), this causes problem (B) when doing (C).

    In that case the user notices (D).

    We can improve this doing (E), because now the user will experience (F),
    which is more desirable."

Please fill in A-F accordingly.

In particular your changelog is missing 'B' and 'D': what exactly is a 
'resource_size_t overflow' and what does the user notice from it?

Your changelog is also missing 'F'.

Thanks,

    Ingo
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diff mbox

Patch

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 8244f013f210..f1c966e05078 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -193,6 +193,7 @@  static bool acpi_decode_space(struct resource_win *win,
 	u8 iodec = attr->granularity == 0xfff ? ACPI_DECODE_10 : ACPI_DECODE_16;
 	bool wp = addr->info.mem.write_protect;
 	u64 len = attr->address_length;
+	u64 start, end, offset = 0;
 	struct resource *res = &win->res;
 
 	/*
@@ -204,9 +205,6 @@  static bool acpi_decode_space(struct resource_win *win,
 		pr_debug("ACPI: Invalid address space min_addr_fix %d, max_addr_fix %d, len %llx\n",
 			 addr->min_address_fixed, addr->max_address_fixed, len);
 
-	res->start = attr->minimum;
-	res->end = attr->maximum;
-
 	/*
 	 * For bridges that translate addresses across the bridge,
 	 * translation_offset is the offset that must be added to the
@@ -214,12 +212,22 @@  static bool acpi_decode_space(struct resource_win *win,
 	 * primary side. Non-bridge devices must list 0 for all Address
 	 * Translation offset bits.
 	 */
-	if (addr->producer_consumer == ACPI_PRODUCER) {
-		res->start += attr->translation_offset;
-		res->end += attr->translation_offset;
-	} else if (attr->translation_offset) {
+	if (addr->producer_consumer == ACPI_PRODUCER)
+		offset = attr->translation_offset;
+	else if (attr->translation_offset)
 		pr_debug("ACPI: translation_offset(%lld) is invalid for non-bridge device.\n",
 			 attr->translation_offset);
+	start = attr->minimum + offset;
+	end = attr->maximum + offset;
+
+	win->offset = offset;
+	res->start = start;
+	res->end = end;
+	if (sizeof(resource_size_t) < sizeof(u64) &&
+	    (offset != win->offset || start != res->start || end != res->end)) {
+		pr_warn("acpi resource window ([%#llx-%#llx] ignored, not CPU addressable)\n",
+			attr->minimum, attr->maximum);
+		return false;
 	}
 
 	switch (addr->resource_type) {
@@ -236,8 +244,6 @@  static bool acpi_decode_space(struct resource_win *win,
 		return false;
 	}
 
-	win->offset = attr->translation_offset;
-
 	if (addr->producer_consumer == ACPI_PRODUCER)
 		res->flags |= IORESOURCE_WINDOW;