Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754646AbbGFPiV (ORCPT ); Mon, 6 Jul 2015 11:38:21 -0400 Received: from terminus.zytor.com ([198.137.202.10]:49114 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753554AbbGFPiS (ORCPT ); Mon, 6 Jul 2015 11:38:18 -0400 Date: Mon, 6 Jul 2015 08:37:27 -0700 From: tip-bot for Andrey Ryabinin Message-ID: Cc: linux-kernel@vger.kernel.org, adech.fo@gmail.com, a.ryabinin@samsung.com, torvalds@linux-foundation.org, alpopov@ptsecurity.com, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, glider@google.com, bp@alien8.de, tglx@linutronix.de, dvyukov@google.com Reply-To: dvyukov@google.com, tglx@linutronix.de, bp@alien8.de, glider@google.com, peterz@infradead.org, hpa@zytor.com, mingo@kernel.org, alpopov@ptsecurity.com, torvalds@linux-foundation.org, a.ryabinin@samsung.com, adech.fo@gmail.com, linux-kernel@vger.kernel.org In-Reply-To: <1435828178-10975-5-git-send-email-a.ryabinin@samsung.com> References: <1435828178-10975-5-git-send-email-a.ryabinin@samsung.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/kasan: Fix boot crash on AMD processors Git-Commit-ID: d4f86beacc21d538dc41e1fc75a22e084f547edf X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2913 Lines: 72 Commit-ID: d4f86beacc21d538dc41e1fc75a22e084f547edf Gitweb: http://git.kernel.org/tip/d4f86beacc21d538dc41e1fc75a22e084f547edf Author: Andrey Ryabinin AuthorDate: Thu, 2 Jul 2015 12:09:36 +0300 Committer: Ingo Molnar 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 Signed-off-by: Andrey Ryabinin Cc: # 4.0+ Cc: Alexander Popov Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Dmitry Vyukov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1435828178-10975-5-git-send-email-a.ryabinin@samsung.com Signed-off-by: Ingo Molnar --- 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/