From patchwork Thu Dec 6 12:24:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10715845 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 E5024109C for ; Thu, 6 Dec 2018 12:26:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D270A292C8 for ; Thu, 6 Dec 2018 12:26:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C5A992BBFB; Thu, 6 Dec 2018 12:26:37 +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 7DB30292C8 for ; Thu, 6 Dec 2018 12:26:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729711AbeLFM0a (ORCPT ); Thu, 6 Dec 2018 07:26:30 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42297 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729712AbeLFMZO (ORCPT ); Thu, 6 Dec 2018 07:25:14 -0500 Received: by mail-wr1-f65.google.com with SMTP id q18so273543wrx.9 for ; Thu, 06 Dec 2018 04:25:13 -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=fxqgizsGn0AaIQnRQ33dQkRGCaY8UuAWu0B6VsH5hUQ=; b=Ujk3SHMZqV7n0tte5Uw8nokkp/oH0FlKFLsFxzElZe9Z0slbPJEAJExlirmXwEUB/j qeFI1DE4ncGLA0+FkTusmS35oYv/U8UXI/jfcSKa3QRtSlDZ5L5lHaiWfjgmPd4nFF/+ vGwiweNbXNO50gJDPLGhzJri8t+wJQe4o/ND+9KUuI2L26oBYQ8hULSaxQMaAnF/iqDX Hpv9wpz9cBx90ytQ87K72yusvxoLQs9ZuSGL0uO4fMjRQ9fR2bvdzrwnlroIA0fQeMGW 0wXe8PTBJ4EYtsNFcnsc8WZUW2aYYzJizcPd8EFhPQh0QD0nyqeteBzhl8XYpy7aMdWS egGA== 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=fxqgizsGn0AaIQnRQ33dQkRGCaY8UuAWu0B6VsH5hUQ=; b=n+a026QnhUHW64rwa6XNUa9zTooYo/2YgaBrUVQmvmgU0UGDyacJDvTs8Ln4e7au7d eL3pX7BobGPt5vkq4DNwFRCPUg2+YCNpfNxt/wA+jPF7EY78HN8esDx1yrYHNcCTMwX4 aShQyjdMgzirYUG4x3+pcGpdDx2wV6hmkndTjCcKY9Ky684BqiOQWlxcEumKdRR/Vv3Z VeMrB7nBSZz1r7fmRgea/pRhf1WScoM4OTyDtv5I07ZgABQNHxus7rxwnatlzmFTXcBM x6aLA2UcwK+gOVzPK0ykka60+SV2++JPP+T3tGmrUj7lRhl3qdOGhnd24cpyAB1esw6B 3EsQ== X-Gm-Message-State: AA+aEWZSLzDvoB6EA29Jx8ZKPFumIdv9ARDKv4ZbR7pss1O/hE65DVmh WqOCFLUa3shlvO6XS/E5JMoQCA== X-Google-Smtp-Source: AFSGD/X/KL+bObt1e53j+RE7+vhNT1qCIPw5uSMB1tFkwSYT/Sx24y8tmABr3/CaYm5nM5Ne2TIj5Q== X-Received: by 2002:adf:b783:: with SMTP id s3mr26257791wre.274.1544099113048; Thu, 06 Dec 2018 04:25:13 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:3180:41f8:3010:ff61]) by smtp.gmail.com with ESMTPSA id j8sm339988wrt.40.2018.12.06.04.25.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Dec 2018 04:25:12 -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 v13 15/25] kasan, mm: perform untagged pointers comparison in krealloc Date: Thu, 6 Dec 2018 13:24:33 +0100 Message-Id: <14f6190d7846186a3506cd66d82446646fe65090.1544099024.git.andreyknvl@google.com> X-Mailer: git-send-email 2.20.0.rc1.387.gf8505762e3-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;