This is a note to let you know that I've just added the patch titled
x86/kasan: Fix boot crash on AMD processors
to the 4.1-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-kasan-fix-boot-crash-on-amd-processors.patch
and it can be found in the queue-4.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From d4f86beacc21d538dc41e1fc75a22e084f547edf Mon Sep 17 00:00:00 2001
From: Andrey Ryabinin <[email protected]>
Date: Thu, 2 Jul 2015 12:09:36 +0300
Subject: x86/kasan: Fix boot crash on AMD processors
From: Andrey Ryabinin <[email protected]>
commit d4f86beacc21d538dc41e1fc75a22e084f547edf upstream.
While populating zero shadow wrong bits in upper level page
tables used. __PAGE_KERNEL_RO that was used for pgd/pud/pmd has
_PAGE_BIT_GLOBAL set. Global bit is present only in the lowest
level of the page translation hierarchy (ptes), and it should be
zero in upper levels.
This bug seems doesn't cause any troubles on Intel cpus, while
on AMDs it cause kernel crash on boot.
Use _KERNPG_TABLE bits for pgds/puds/pmds to fix this.
Reported-by: Borislav Petkov <[email protected]>
Signed-off-by: Andrey Ryabinin <[email protected]>
Cc: Alexander Popov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/x86/mm/kasan_init_64.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -85,7 +85,7 @@ static int __init zero_pmd_populate(pud_
while (IS_ALIGNED(addr, PMD_SIZE) && addr + PMD_SIZE <= end) {
WARN_ON(!pmd_none(*pmd));
set_pmd(pmd, __pmd(__pa_nodebug(kasan_zero_pte)
- | __PAGE_KERNEL_RO));
+ | _KERNPG_TABLE));
addr += PMD_SIZE;
pmd = pmd_offset(pud, addr);
}
@@ -111,7 +111,7 @@ static int __init zero_pud_populate(pgd_
while (IS_ALIGNED(addr, PUD_SIZE) && addr + PUD_SIZE <= end) {
WARN_ON(!pud_none(*pud));
set_pud(pud, __pud(__pa_nodebug(kasan_zero_pmd)
- | __PAGE_KERNEL_RO));
+ | _KERNPG_TABLE));
addr += PUD_SIZE;
pud = pud_offset(pgd, addr);
}
@@ -136,7 +136,7 @@ static int __init zero_pgd_populate(unsi
while (IS_ALIGNED(addr, PGDIR_SIZE) && addr + PGDIR_SIZE <= end) {
WARN_ON(!pgd_none(*pgd));
set_pgd(pgd, __pgd(__pa_nodebug(kasan_zero_pud)
- | __PAGE_KERNEL_RO));
+ | _KERNPG_TABLE));
addr += PGDIR_SIZE;
pgd = pgd_offset_k(addr);
}
Patches currently in stable-queue which might be from [email protected] are
queue-4.1/x86-kasan-fix-kasan-shadow-region-page-tables.patch
queue-4.1/x86-kasan-fix-boot-crash-on-amd-processors.patch
queue-4.1/x86-init-clear-init_level4_pgt-earlier.patch
queue-4.1/x86-kasan-flush-tlbs-after-switching-cr3.patch
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