Commit-ID: d4f86beacc21d538dc41e1fc75a22e084f547edf Gitweb: http://git.kernel.org/tip/d4f86beacc21d538dc41e1fc75a22e084f547edf Author: Andrey Ryabinin <[email protected]> AuthorDate: Thu, 2 Jul 2015 12:09:36 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 6 Jul 2015 14:53:14 +0200
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 <[email protected]> Signed-off-by: Andrey Ryabinin <[email protected]> Cc: <[email protected]> # 4.0+ 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]> --- arch/x86/mm/kasan_init_64.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 5d26642..9a54dbe 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
