From patchwork Thu Feb 2 04:42:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13125273 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 4F71AC64EC3 for ; Thu, 2 Feb 2023 04:44:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231513AbjBBEoJ (ORCPT ); Wed, 1 Feb 2023 23:44:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231486AbjBBEoF (ORCPT ); Wed, 1 Feb 2023 23:44:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D91E7C73F; Wed, 1 Feb 2023 20:43:51 -0800 (PST) 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 04B1AB8241B; Thu, 2 Feb 2023 04:43:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E379C4339E; Thu, 2 Feb 2023 04:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675313028; bh=3jGoUYb5ZXXZkAA7E72JChHDGyEWYUsA360wTbKvQOo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FIqlkGAjxOmAJ97Zovh+TPaze9M0KI4n65AH/v7tUvMHAYqucSztv9HtRFnLwcBrU 3WqsXIsi/KPRVzGBNa6ZFHiFbiU6W31p2Fg1/G9ZHszwR2F5nmTwwPTmnvtjl5UME8 aR+umkpiBFHZPrINcn33lds233qs08T2QoKpgN8VfDwS2CC2bNuOgqoFvPQerf23qW sCnp0aYHz0bIBDyNK2LzqD1EbOXZa1JksNWGTqxpXvbTZWA45QJB8q8DQQpEoIWAnM 8mGcqfjNNNogf7BbhshMK4etUtq7mAxBxfptwNFVZLxb1iUurzzxKsKklFpZ+KCDD0 3yd4+seZdW77w== From: Eric Biggers To: stable@vger.kernel.org Cc: Harshit Mogalapalli , Kees Cook , SeongJae Park , Seth Jenkins , Jann Horn , "Eric W . Biederman" , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Andrey Ryabinin , Dmitry Vyukov , Ingo Molnar , Juri Lelli , Patricia Alfonso , Peter Zijlstra , Shuah Khan , Vincent Guittot , David Gow , Andrew Morton , Andrey Konovalov , Brendan Higgins , Linus Torvalds Subject: [PATCH 5.4 03/17] mm: kasan: do not panic if both panic_on_warn and kasan_multishot set Date: Wed, 1 Feb 2023 20:42:41 -0800 Message-Id: <20230202044255.128815-4-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230202044255.128815-1-ebiggers@kernel.org> References: <20230202044255.128815-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: David Gow commit be4f1ae978ffe98cc95ec49ceb95386fb4474974 upstream. KASAN errors will currently trigger a panic when panic_on_warn is set. This renders kasan_multishot useless, as further KASAN errors won't be reported if the kernel has already paniced. By making kasan_multishot disable this behaviour for KASAN errors, we can still have the benefits of panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot. This is particularly important when running KASAN tests, which need to trigger multiple KASAN errors: previously these would panic the system if panic_on_warn was set, now they can run (and will panic the system should non-KASAN warnings show up). Signed-off-by: David Gow Signed-off-by: Andrew Morton Tested-by: Andrey Konovalov Reviewed-by: Andrey Konovalov Reviewed-by: Brendan Higgins Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Juri Lelli Cc: Patricia Alfonso Cc: Peter Zijlstra Cc: Shuah Khan Cc: Vincent Guittot Link: https://lkml.kernel.org/r/20200915035828.570483-6-davidgow@google.com Link: https://lkml.kernel.org/r/20200910070331.3358048-6-davidgow@google.com Signed-off-by: Linus Torvalds Signed-off-by: Eric Biggers --- mm/kasan/report.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 621782100eaa0..a05ff1922d499 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -92,7 +92,7 @@ static void end_report(unsigned long *flags) pr_err("==================================================================\n"); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irqrestore(&report_lock, *flags); - if (panic_on_warn) + if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) panic("panic_on_warn set ...\n"); kasan_enable_current(); }