From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48E91CCA47C for ; Mon, 4 Jul 2022 01:09:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232569AbiGDBJo (ORCPT ); Sun, 3 Jul 2022 21:09:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229939AbiGDBJl (ORCPT ); Sun, 3 Jul 2022 21:09:41 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DCF962F3 for ; Sun, 3 Jul 2022 18:09:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0BEA6B80C73 for ; Mon, 4 Jul 2022 01:09:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C5C8C341C6; Mon, 4 Jul 2022 01:09:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1656896977; bh=Yi3RLqElHa9YJlf4/p6dv8jLmN+tor3rGdykb5k6V9I=; h=Date:To:From:Subject:From; b=mvitP/LwtB5XBJMbhAsVZrtuwdmNol0zYf1xtG81/2E/o2/qlCDpDGBIclkfl7K1X p+TqmhSHUf/XjSeXNDaCcqqnkIV3P0lMW+dcSofzu0T4PAsmBtAuy0/pb5BMCFwCLD wHXG7WZ7lvTUbM9peYyt/U5kS0YUaIrkd7JcNS/8= Date: Sun, 03 Jul 2022 18:09:37 -0700 To: mm-commits@vger.kernel.org, ryabinin.a.a@gmail.com, glider@google.com, elver@google.com, dvyukov@google.com, andreyknvl@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] kasan-fix-zeroing-vmalloc-memory-with-hw_tags.patch removed from -mm tree Message-Id: <20220704010937.9C5C8C341C6@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: kasan: fix zeroing vmalloc memory with HW_TAGS has been removed from the -mm tree. Its filename was kasan-fix-zeroing-vmalloc-memory-with-hw_tags.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Andrey Konovalov Subject: kasan: fix zeroing vmalloc memory with HW_TAGS Date: Thu, 9 Jun 2022 20:18:47 +0200 HW_TAGS KASAN skips zeroing page_alloc allocations backing vmalloc mappings via __GFP_SKIP_ZERO. Instead, these pages are zeroed via kasan_unpoison_vmalloc() by passing the KASAN_VMALLOC_INIT flag. The problem is that __kasan_unpoison_vmalloc() does not zero pages when either kasan_vmalloc_enabled() or is_vmalloc_or_module_addr() fail. Thus: 1. Change __vmalloc_node_range() to only set KASAN_VMALLOC_INIT when __GFP_SKIP_ZERO is set. 2. Change __kasan_unpoison_vmalloc() to always zero pages when the KASAN_VMALLOC_INIT flag is set. 3. Add WARN_ON() asserts to check that KASAN_VMALLOC_INIT cannot be set in other early return paths of __kasan_unpoison_vmalloc(). Also clean up the comment in __kasan_unpoison_vmalloc. Link: https://lkml.kernel.org/r/4bc503537efdc539ffc3f461c1b70162eea31cf6.1654798516.git.andreyknvl@google.com Fixes: 23689e91fb22 ("kasan, vmalloc: add vmalloc tagging for HW_TAGS") Signed-off-by: Andrey Konovalov Cc: Marco Elver Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Andrey Ryabinin Signed-off-by: Andrew Morton --- mm/kasan/hw_tags.c | 32 +++++++++++++++++++++++--------- mm/vmalloc.c | 10 +++++----- 2 files changed, 28 insertions(+), 14 deletions(-) --- a/mm/kasan/hw_tags.c~kasan-fix-zeroing-vmalloc-memory-with-hw_tags +++ a/mm/kasan/hw_tags.c @@ -257,27 +257,37 @@ static void unpoison_vmalloc_pages(const } } +static void init_vmalloc_pages(const void *start, unsigned long size) +{ + const void *addr; + + for (addr = start; addr < start + size; addr += PAGE_SIZE) { + struct page *page = virt_to_page(addr); + + clear_highpage_kasan_tagged(page); + } +} + void *__kasan_unpoison_vmalloc(const void *start, unsigned long size, kasan_vmalloc_flags_t flags) { u8 tag; unsigned long redzone_start, redzone_size; - if (!kasan_vmalloc_enabled()) - return (void *)start; - - if (!is_vmalloc_or_module_addr(start)) + if (!kasan_vmalloc_enabled() || !is_vmalloc_or_module_addr(start)) { + if (flags & KASAN_VMALLOC_INIT) + init_vmalloc_pages(start, size); return (void *)start; + } /* - * Skip unpoisoning and assigning a pointer tag for non-VM_ALLOC - * mappings as: + * Don't tag non-VM_ALLOC mappings, as: * * 1. Unlike the software KASAN modes, hardware tag-based KASAN only * supports tagging physical memory. Therefore, it can only tag a * single mapping of normal physical pages. * 2. Hardware tag-based KASAN can only tag memory mapped with special - * mapping protection bits, see arch_vmalloc_pgprot_modify(). + * mapping protection bits, see arch_vmap_pgprot_tagged(). * As non-VM_ALLOC mappings can be mapped outside of vmalloc code, * providing these bits would require tracking all non-VM_ALLOC * mappers. @@ -289,15 +299,19 @@ void *__kasan_unpoison_vmalloc(const voi * * For non-VM_ALLOC allocations, page_alloc memory is tagged as usual. */ - if (!(flags & KASAN_VMALLOC_VM_ALLOC)) + if (!(flags & KASAN_VMALLOC_VM_ALLOC)) { + WARN_ON(flags & KASAN_VMALLOC_INIT); return (void *)start; + } /* * Don't tag executable memory. * The kernel doesn't tolerate having the PC register tagged. */ - if (!(flags & KASAN_VMALLOC_PROT_NORMAL)) + if (!(flags & KASAN_VMALLOC_PROT_NORMAL)) { + WARN_ON(flags & KASAN_VMALLOC_INIT); return (void *)start; + } tag = kasan_random_tag(); start = set_tag(start, tag); --- a/mm/vmalloc.c~kasan-fix-zeroing-vmalloc-memory-with-hw_tags +++ a/mm/vmalloc.c @@ -3161,15 +3161,15 @@ again: /* * Mark the pages as accessible, now that they are mapped. - * The init condition should match the one in post_alloc_hook() - * (except for the should_skip_init() check) to make sure that memory - * is initialized under the same conditions regardless of the enabled - * KASAN mode. + * The condition for setting KASAN_VMALLOC_INIT should complement the + * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check + * to make sure that memory is initialized under the same conditions. * Tag-based KASAN modes only assign tags to normal non-executable * allocations, see __kasan_unpoison_vmalloc(). */ kasan_flags |= KASAN_VMALLOC_VM_ALLOC; - if (!want_init_on_free() && want_init_on_alloc(gfp_mask)) + if (!want_init_on_free() && want_init_on_alloc(gfp_mask) && + (gfp_mask & __GFP_SKIP_ZERO)) kasan_flags |= KASAN_VMALLOC_INIT; /* KASAN_VMALLOC_PROT_NORMAL already set if required. */ area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags); _ Patches currently in -mm which might be from andreyknvl@google.com are