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authorAndrey Ryabinin <a.ryabinin@samsung.com>2015-07-02 12:09:36 +0300
committerIngo Molnar <mingo@kernel.org>2015-07-06 14:53:14 +0200
commitd4f86beacc21d538dc41e1fc75a22e084f547edf (patch)
tree0075dd342992957e826d16116f58f582d879c433
parent241d2c54c62fa0939fc9a9512b48ac3434e90a89 (diff)
downloadlinux-next-d4f86beacc21d538dc41e1fc75a22e084f547edf.tar.gz
x86/kasan: Fix boot crash on AMD processors
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 <bp@alien8.de> Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: <stable@vger.kernel.org> # 4.0+ Cc: Alexander Popov <alpopov@ptsecurity.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1435828178-10975-5-git-send-email-a.ryabinin@samsung.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/mm/kasan_init_64.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index 5d26642e4e8a..9a54dbe98064 100644
--- 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_t *pud, unsigned long addr,
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_t *pgd, unsigned long addr,
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(unsigned long addr, unsigned long end)
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);
}