From patchwork Tue Nov 6 17:30:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10670995 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0B43D15E9 for ; Tue, 6 Nov 2018 17:32:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA78B2ABEB for ; Tue, 6 Nov 2018 17:32:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE4AF2ABFF; Tue, 6 Nov 2018 17:32:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8CC792ABF9 for ; Tue, 6 Nov 2018 17:32:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389797AbeKGC5W (ORCPT ); Tue, 6 Nov 2018 21:57:22 -0500 Received: from mail-wr1-f68.google.com ([209.85.221.68]:33559 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389816AbeKGC5V (ORCPT ); Tue, 6 Nov 2018 21:57:21 -0500 Received: by mail-wr1-f68.google.com with SMTP id u9-v6so4131468wrr.0 for ; Tue, 06 Nov 2018 09:31:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wyLKUPGn9jgKs5kyhcnEkFlESwFUwxhfNlag9MpDnKY=; b=NdZcOdV+SeQJsPz94m7H4XbZIwYUVU7yfboopa1Zjkyz1uIe2LlTLBqR71KPODjk4w w2i8lDUlVZAZkkOc9R+Q3ZJezDsbmPNngjH5GGihgainLZsCuwZov11A/67GWeqlJcfq +nbTxxtex/VSTC6mj0qA21CD7O1h+ebTAPCJNL2lovRDEHcZNUuJySqcFbS+ZbxwDr/E K2ifbpcrlmfB0NCeAVLhsJelIHCbITz8Q/LhoU36zDmoN+csn7I9AlcesdomO9yOLYsd khQiU+Km8JaWBY1mrboUqf+Qb5s/GZ9L6HQqsuN/RYVQLW821T971uEQ1HkkHYY5Jlsp V76w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wyLKUPGn9jgKs5kyhcnEkFlESwFUwxhfNlag9MpDnKY=; b=XbK4SX/Bm2IBkZAf/P078NxctXo+VMfsn4lLbUjE6AcQDIOs8Y0NzncySMQ2eiRlss JlfS9DUwCvWeDyTEbjuktAcaVwhKKG3nwIUAGBQ0Xo6VSOMm8YLHvy/iR0OOoH211iFw pvQ8+xLB8zHK1KanyJQ3Xq8i1SXWXSUSUYNZtQHv7DbijGsw5aoBcVdEgGo7vZ36Mao6 CbGg/Ab7NK+ix4TCQthPR9sF8VLkz/3EV0Sf2Yv9RBAnh5EVeTmVEY+YrswoFLy+V6Ln 7R1d+lEpuqlgAloLnv1KN7PcHRh6q0ss2nFkm2Tqyi9JIWHKe9+KKd5tnCPe+7s1zm9e 8V5A== X-Gm-Message-State: AGRZ1gJs1JZTPPWaNxzgvMfSeL1BdHI/S/rt//HwZ2WN1Vm7LKxkT9oO pikrm7WsD4M+JBUAHPNQraT0LQ== X-Google-Smtp-Source: AJdET5d8EgWArhBW85rMDSm87h+TZuEVQo4IoirzvQvLb/UzVNBtYXRv1TEEXHRWUFUXNfkKIR1brQ== X-Received: by 2002:a5d:6551:: with SMTP id z17-v6mr20589467wrv.231.1541525464645; Tue, 06 Nov 2018 09:31:04 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id z17-v6sm16328416wrm.65.2018.11.06.09.31.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Nov 2018 09:31:03 -0800 (PST) From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan , Andrey Konovalov Subject: [PATCH v10 14/22] kasan, mm: perform untagged pointers comparison in krealloc Date: Tue, 6 Nov 2018 18:30:29 +0100 Message-Id: <1d9612a508dd95248cc1cd3b4a4b332b4a198212.1541525354.git.andreyknvl@google.com> X-Mailer: git-send-email 2.19.1.930.g4563a0d9d0-goog In-Reply-To: References: MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The krealloc function checks where the same buffer was reused or a new one allocated by comparing kernel pointers. Tag-based KASAN changes memory tag on the krealloc'ed chunk of memory and therefore also changes the pointer tag of the returned pointer. Therefore we need to perform comparison on untagged (with tags reset) pointers to check whether it's the same memory region or not. Reviewed-by: Andrey Ryabinin Reviewed-by: Dmitry Vyukov Signed-off-by: Andrey Konovalov --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 5f3504e26d4c..5aabcbd32d82 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1534,7 +1534,7 @@ void *krealloc(const void *p, size_t new_size, gfp_t flags) } ret = __do_krealloc(p, new_size, flags); - if (ret && p != ret) + if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret)) kfree(p); return ret;