This is a note to let you know that I have just added a patch titled
x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE
to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11.11.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From a13efdf8c8755ee180bed9684ada17343c5dd8bf Mon Sep 17 00:00:00 2001
From: Dexuan Cui <decui@xxxxxxxxxxxxx>
Date: Wed, 29 Oct 2014 03:53:37 -0700
Subject: x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE
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 <decui@xxxxxxxxxxxxx>
Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: gregkh@xxxxxxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: olaf@xxxxxxxxx
Cc: apw@xxxxxxxxxxxxx
Cc: jasowang@xxxxxxxxxx
Cc: dave.hansen@xxxxxxxxx
Cc: riel@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
arch/x86/mm/pageattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index bb32480..aabdf76 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -389,7 +389,7 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr)
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);
--
1.9.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>