From patchwork Fri Mar 25 01:13:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12791191 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10E09C433F5 for ; Fri, 25 Mar 2022 01:13:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 930C78D0031; Thu, 24 Mar 2022 21:13:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8DDC58D0005; Thu, 24 Mar 2022 21:13:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7CD068D0031; Thu, 24 Mar 2022 21:13:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0230.hostedemail.com [216.40.44.230]) by kanga.kvack.org (Postfix) with ESMTP id 6CFEA8D0005 for ; Thu, 24 Mar 2022 21:13:12 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 2BE2A1828D834 for ; Fri, 25 Mar 2022 01:13:12 +0000 (UTC) X-FDA: 79281135024.16.DD6F7E3 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf31.hostedemail.com (Postfix) with ESMTP id 6167F20035 for ; Fri, 25 Mar 2022 01:13:11 +0000 (UTC) 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 sin.source.kernel.org (Postfix) with ESMTPS id E48D5CE2811; Fri, 25 Mar 2022 01:13:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E16DC340EC; Fri, 25 Mar 2022 01:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648170787; bh=3cEh8+GuNzhEDIy7//ZmGiV8sEVo+MniwLiEh9BCNXo=; h=Date:To:From:In-Reply-To:Subject:From; b=GKM1X+9aIvDs4A//nYka4XZqTpvxID63zpML0uO1XSiZSDo+gX9WIMqafTE0ZeTQe 4J1E/td+r6Ff2KobPIAuVUNas6fQ3AW3WEzWhpu/SV++1NhuNQlDDEIA3vUVNer3pe kxCvl4klN44Njc4rtLKt84iq3Hy70dbAXmI8UMLU= Date: Thu, 24 Mar 2022 18:13:06 -0700 To: ryabinin.a.a@gmail.com,glider@google.com,elver@google.com,dvyukov@google.com,andreyknvl@google.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220324180758.96b1ac7e17675d6bc474485e@linux-foundation.org> Subject: [patch 091/114] kasan: respect KASAN_BIT_REPORTED in all reporting routines Message-Id: <20220325011307.4E16DC340EC@smtp.kernel.org> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 6167F20035 X-Rspam-User: Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=GKM1X+9a; dmarc=none; spf=pass (imf31.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.73.55 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Stat-Signature: 8o4oqtgi65bs8zft8dz1redirw7me9zh X-HE-Tag: 1648170791-979662 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: From: Andrey Konovalov Subject: kasan: respect KASAN_BIT_REPORTED in all reporting routines Currently, only kasan_report() checks the KASAN_BIT_REPORTED and KASAN_BIT_MULTI_SHOT flags. Make other reporting routines check these flags as well. Also add explanatory comments. Note that the current->kasan_depth check is split out into report_suppressed() and only called for kasan_report(). Link: https://lkml.kernel.org/r/715e346b10b398e29ba1b425299dcd79e29d58ce.1646237226.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Marco Elver Signed-off-by: Andrew Morton --- mm/kasan/report.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) --- a/mm/kasan/report.c~kasan-respect-kasan_bit_reported-in-all-reporting-routines +++ a/mm/kasan/report.c @@ -381,12 +381,26 @@ static void print_memory_metadata(const } } -static bool report_enabled(void) +/* + * Used to suppress reports within kasan_disable/enable_current() critical + * sections, which are used for marking accesses to slab metadata. + */ +static bool report_suppressed(void) { #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) if (current->kasan_depth) - return false; + return true; #endif + return false; +} + +/* + * Used to avoid reporting more than one KASAN bug unless kasan_multi_shot + * is enabled. Note that KASAN tests effectively enable kasan_multi_shot + * for their duration. + */ +static bool report_enabled(void) +{ if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) return true; return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); @@ -416,6 +430,14 @@ void kasan_report_invalid_free(void *ptr unsigned long flags; struct kasan_report_info info; + /* + * Do not check report_suppressed(), as an invalid-free cannot be + * caused by accessing slab metadata and thus should not be + * suppressed by kasan_disable/enable_current() critical sections. + */ + if (unlikely(!report_enabled())) + return; + start_report(&flags, true); info.type = KASAN_REPORT_INVALID_FREE; @@ -444,7 +466,7 @@ bool kasan_report(unsigned long addr, si unsigned long irq_flags; struct kasan_report_info info; - if (unlikely(!report_enabled())) { + if (unlikely(report_suppressed()) || unlikely(!report_enabled())) { ret = false; goto out; } @@ -473,6 +495,13 @@ void kasan_report_async(void) { unsigned long flags; + /* + * Do not check report_suppressed(), as kasan_disable/enable_current() + * critical sections do not affect Hardware Tag-Based KASAN. + */ + if (unlikely(!report_enabled())) + return; + start_report(&flags, false); pr_err("BUG: KASAN: invalid-access\n"); pr_err("Asynchronous fault: no details available\n");