From patchwork Mon Nov 2 16:04:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 11874293 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 57819697 for ; Mon, 2 Nov 2020 16:05:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C56C22258 for ; Mon, 2 Nov 2020 16:05:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="BSLt9OKa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C56C22258 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 548E56B00A6; Mon, 2 Nov 2020 11:05:22 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 4CE876B00A7; Mon, 2 Nov 2020 11:05:22 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2D2816B00A8; Mon, 2 Nov 2020 11:05:22 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id E9D6A6B00A6 for ; Mon, 2 Nov 2020 11:05:21 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 5DC363631 for ; Mon, 2 Nov 2020 16:05:21 +0000 (UTC) X-FDA: 77439952842.20.jail90_24082b6272b1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 2DD87180C07A3 for ; Mon, 2 Nov 2020 16:05:21 +0000 (UTC) X-Spam-Summary: 1,0,0,1b4644cdea43df8a,d41d8cd98f00b204,3py6gxwokcca6j9naugjrhckkcha.8kihejqt-iigr68g.knc@flex--andreyknvl.bounces.google.com,,RULES_HIT:41:69:152:355:379:541:800:960:965:966:968:973:988:989:1042:1260:1277:1313:1314:1345:1359:1431:1437:1516:1518:1535:1543:1593:1594:1711:1730:1747:1777:1792:1981:2194:2196:2199:2200:2393:2559:2562:3138:3139:3140:3141:3142:3152:3355:3865:3866:3870:3871:4118:4250:4321:4385:4390:4395:4605:5007:6261:6653:6742:8603:9592:9969:10004:10400:10450:10455:11026:11232:11473:11658:11914:12043:12296:12297:12438:12555:12895:12986:14181:14394:14659:14721:19904:19999:21080:21324:21365:21444:21451:21627:21772:21990:30003:30012:30054:30070:30075,0,RBL:209.85.221.74:@flex--andreyknvl.bounces.google.com:.lbl8.mailshell.net-62.18.0.100 66.100.201.100;04yrgkdrkgc1zehmfnej6g7e5jr38ypy5pow3utkfuttq979ue8hwxotn4rj8e6.7339wnb5d4embongw9wgey71su6485u3m11bobxyshhnr91sx1gjr6npejwf5ii.r-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netch eck:none X-HE-Tag: jail90_24082b6272b1 X-Filterd-Recvd-Size: 7209 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Mon, 2 Nov 2020 16:05:20 +0000 (UTC) Received: by mail-wr1-f74.google.com with SMTP id v5so6654009wrr.0 for ; Mon, 02 Nov 2020 08:05:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=JrbTjwkrdKqcTf3OBQQXqXKZQLwLc5XAsTu4uoIDNkU=; b=BSLt9OKaearay+FGWxrm4o7h2bkHk/gdUbGPcfYRGHQdZUj8sw/1erDb+9+jujTLw0 Ug225r6/pntadIDfVbDTace6LXDbzEzYtWFc9wcVlA+lolJ0moGKw3h0zScXyFynl9CB BQp4ViTMUAR7sTv9TbxNtHPnaqAT9H3yUKkYK08j0+ZXg5Ar/OwpIWVEdsJE5FxizL4S WS2h9maD5lysR8dijjWXKPQLDA59x7DKG1WXtqkgetf/O6iCGhGmLmer1316cHGTushF CNq7JLufAyz95XwjMEHNNtSYSt2k+XIy1UfP8Key0nYicM3iGFpuQnzO/Rtd0FJq+vYk nlnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=JrbTjwkrdKqcTf3OBQQXqXKZQLwLc5XAsTu4uoIDNkU=; b=fwtALAoof4VEoJWH3/XSexRJq+iNjLY6zb3q5QPmxGOT94e3gC311nhFNiAeNxp5A+ N2LbSoLoDO0GB8YMAHjpmquuwMAVMAeB6TuE2rBKsE8KFpZXbvl6hXf7JtwBPYRPUlHN hh1oaFOsUl7gJemu/Ih8qsXT3i0mRJWpuj6m+DhmTAMGp53oAgFl1t9+a1gAprWs3kUu 1Z3CHFmel8R/fyqc1vdiLSRpSE98NUYl5tGKite1ZKRqQ3JQ5P3Jp/IppsVozPKx8RV6 VSPJDRbcM18nHlfWXk7aUjBYm98pMD8I/usp6fyp5HbNUXDpFwwXHoXZS+/caloA8QnR 8hUw== X-Gm-Message-State: AOAM532pqqrZhaWgb6OXIBJHos0A2pIdnAJ9Ms8AXwu38m6oz/n+kC8+ MJtPFGsZv9QaVEdIqbeB3e8cwfj3BKLC9/3Z X-Google-Smtp-Source: ABdhPJyOvs6s9ctpkM6Ce8d6mYTqLAZR/nAOMWlFghuqE5Zo1zLXZqWjNGBUbKu6n2PsowbXwY5h/PzVQRvYgQue X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:a5d:6a85:: with SMTP id s5mr21657731wru.90.1604333119324; Mon, 02 Nov 2020 08:05:19 -0800 (PST) Date: Mon, 2 Nov 2020 17:04:02 +0100 In-Reply-To: Message-Id: <499c0824a10e32c7dbb29c2f28e9a76c771c0da0.1604333009.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.29.1.341.ge80a0c044ae-goog Subject: [PATCH v7 22/41] kasan: hide invalid free check implementation From: Andrey Konovalov To: Catalin Marinas , Will Deacon Cc: Vincenzo Frascino , kasan-dev@googlegroups.com, Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Elena Petrova , Branislav Rankov , Kevin Brodsky , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. For software KASAN modes the check is based on the value in the shadow memory. Hardware tag-based KASAN won't be using shadow, so hide the implementation of the check in check_invalid_free(). Also simplify the code for software tag-based mode. No functional changes for software modes. Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver --- Change-Id: I5fae9531c9fc948eb4d4e0c589744032fc5a0789 --- mm/kasan/common.c | 19 +------------------ mm/kasan/generic.c | 7 +++++++ mm/kasan/kasan.h | 2 ++ mm/kasan/sw_tags.c | 9 +++++++++ 4 files changed, 19 insertions(+), 18 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 123abfb760d4..543e6bf2168f 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -272,25 +272,9 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, return (void *)object; } -static inline bool shadow_invalid(u8 tag, s8 shadow_byte) -{ - if (IS_ENABLED(CONFIG_KASAN_GENERIC)) - return shadow_byte < 0 || - shadow_byte >= KASAN_GRANULE_SIZE; - - /* else CONFIG_KASAN_SW_TAGS: */ - if ((u8)shadow_byte == KASAN_TAG_INVALID) - return true; - if ((tag != KASAN_TAG_KERNEL) && (tag != (u8)shadow_byte)) - return true; - - return false; -} - static bool __kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip, bool quarantine) { - s8 shadow_byte; u8 tag; void *tagged_object; unsigned long rounded_up_size; @@ -309,8 +293,7 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object, if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) return false; - shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); - if (shadow_invalid(tag, shadow_byte)) { + if (check_invalid_free(tagged_object)) { kasan_report_invalid_free(tagged_object, ip); return true; } diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index ec4417156943..e1af3b6c53b8 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -187,6 +187,13 @@ bool check_memory_region(unsigned long addr, size_t size, bool write, return check_memory_region_inline(addr, size, write, ret_ip); } +bool check_invalid_free(void *addr) +{ + s8 shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr)); + + return shadow_byte < 0 || shadow_byte >= KASAN_GRANULE_SIZE; +} + void kasan_cache_shrink(struct kmem_cache *cache) { quarantine_remove_cache(cache); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index d8f54efb2899..04df1481a033 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -164,6 +164,8 @@ void kasan_poison_memory(const void *address, size_t size, u8 value); bool check_memory_region(unsigned long addr, size_t size, bool write, unsigned long ret_ip); +bool check_invalid_free(void *addr); + void *find_first_bad_addr(void *addr, size_t size); const char *get_bug_type(struct kasan_access_info *info); diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c index 4bdd7dbd6647..b2638c2cd58a 100644 --- a/mm/kasan/sw_tags.c +++ b/mm/kasan/sw_tags.c @@ -121,6 +121,15 @@ bool check_memory_region(unsigned long addr, size_t size, bool write, return true; } +bool check_invalid_free(void *addr) +{ + u8 tag = get_tag(addr); + u8 shadow_byte = READ_ONCE(*(u8 *)kasan_mem_to_shadow(reset_tag(addr))); + + return (shadow_byte == KASAN_TAG_INVALID) || + (tag != KASAN_TAG_KERNEL && tag != shadow_byte); +} + #define DEFINE_HWASAN_LOAD_STORE(size) \ void __hwasan_load##size##_noabort(unsigned long addr) \ { \