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

    x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE

to the 3.17-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:
     x86-pageattr-prevent-overflow-in-slow_virt_to_phys-for-x86_pae.patch
and it can be found in the queue-3.17 subdirectory.

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


>From d1cd1210834649ce1ca6bafe5ac25d2f40331343 Mon Sep 17 00:00:00 2001
From: Dexuan Cui <[email protected]>
Date: Wed, 29 Oct 2014 03:53:37 -0700
Subject: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE

From: Dexuan Cui <[email protected]>

commit d1cd1210834649ce1ca6bafe5ac25d2f40331343 upstream.

pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long <<
PAGE_SHIFT" will overflow for PFNs above 4GB.

Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V,
with 5GB memory assigned, can't load the netvsc driver successfully and
hence the synthetic network device can't work (we can use the kernel parameter
mem=3000M to work around the issue).

Cast pte_pfn() to phys_addr_t before shifting.

Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()"
Signed-off-by: Dexuan Cui <[email protected]>
Cc: K. Y. Srinivasan <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/x86/mm/pageattr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -409,7 +409,7 @@ phys_addr_t slow_virt_to_phys(void *__vi
        psize = page_level_size(level);
        pmask = page_level_mask(level);
        offset = virt_addr & ~pmask;
-       phys_addr = pte_pfn(*pte) << PAGE_SHIFT;
+       phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
        return (phys_addr | offset);
 }
 EXPORT_SYMBOL_GPL(slow_virt_to_phys);


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

queue-3.17/x86-pageattr-prevent-overflow-in-slow_virt_to_phys-for-x86_pae.patch
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