From nobody Sun Apr 19 21:58:29 2026 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 9FC15C433EF for ; Sun, 26 Jun 2022 17:04:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230477AbiFZREY (ORCPT ); Sun, 26 Jun 2022 13:04:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbiFZREW (ORCPT ); Sun, 26 Jun 2022 13:04:22 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A8B365B0 for ; Sun, 26 Jun 2022 10:04:20 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id jb13so6219454plb.9 for ; Sun, 26 Jun 2022 10:04:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=oFSj1F+cvrzuMgRbVJtsNeMg49O8qOKUhwSEI2b4t3A=; b=AAAVJXiWm0mI22Obyyka3npjSQpUd0V4kOn5WabIA9uexHD2iTu3QRHzp4QbMeRPrY X1lHSwmTz4tXsZL218ctZS6l08r5yvdfO79xjCzGMZKi/EbMWxOTF471l7B6s5VAv6xb m0h2G4w8s88tfp3W4cIJdui34XiqWjNlGz+DdRMw+WyYQjmadhkfI+kszeXaYXwr4Xeh kOrKCGuSaCwLCqE+1uHDi1xpcO3xOIgmMZf4ULVqH6D2tjTHLDO/dD7uFPbwPfhqw+dJ ptuuH7q6STg3Yc5UP966PHv2uy2qmMM4VrabzcQE/rH6dk0i66AcW6hTFT4ZwzgJrSlM ugNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=oFSj1F+cvrzuMgRbVJtsNeMg49O8qOKUhwSEI2b4t3A=; b=TtUq2N2T/4HPwsh0c+OOcFCz2bePGUP6UZ7mRqQmyOcMzUX9zPsJbpEgFYuSA4e2OY 5vSfHlOnmlG15WQ4HdfqhYutbLsI8d2QSg/uvczzmu3HrBfKnls85LWONgJQ6iMaHpZy klJc3TlelqL5DA8B+XUWrwkNA+2iglJdDo9tnbdLZQNhUWeZVZyV9BbKgrhBk8ysFv9I 9I/SmNbPEz+Nsv7yo8KnjnhPXTwAWzDyo31RZY+hOPcbQObbdPDVPRJny0EnVVeqwj5R bRDnrErEdqlgSMwHrE/lNQL4wI7YWQ8PWO1TGz7mQPGua7vbENRrqH7L7qe8mqDcMx/k HRyg== X-Gm-Message-State: AJIora8Et4gskF/TWxb3KUFHTf+u9V+jGcs7UtRkJOXrP/mDmNWyTO6T 9jo0jBMgUEM4uyxAb9GhHag= X-Google-Smtp-Source: AGRyM1tKL2KuV8DoR1i9GFOsuCXwvQGfLQ8tkqPLgkBnj6SuZzWxtHs6KKsGDaOdbLnlj+dlimVHKQ== X-Received: by 2002:a17:90a:5b0d:b0:1ea:d1ed:186e with SMTP id o13-20020a17090a5b0d00b001ead1ed186emr10676962pji.240.1656263059833; Sun, 26 Jun 2022 10:04:19 -0700 (PDT) Received: from fedora.. ([103.230.148.188]) by smtp.gmail.com with ESMTPSA id ms3-20020a17090b234300b001ead46e77e2sm5450642pjb.13.2022.06.26.10.04.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Jun 2022 10:04:18 -0700 (PDT) From: Gautam Menghani To: ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, vincenzo.frascino@arm.com, akpm@linux-foundation.org Cc: Gautam Menghani , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org Subject: [PATCH] mm/kasan: Fix null pointer dereference warning in qlink_to_cache() Date: Sun, 26 Jun 2022 22:33:55 +0530 Message-Id: <20220626170355.198913-1-gautammenghani201@gmail.com> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The function virt_to_slab() declared in slab.h can return NULL if the address does not belong to a slab. This case is not handled in the function qlink_to_cache() in the file quarantine.c, which can cause a NULL pointer dereference in "virt_to_slab(qlink)->slab_cache".=20 This issue was discovered by fanalyzer (my gcc version: 12.1.1 20220507) Signed-off-by: Gautam Menghani --- mm/kasan/quarantine.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 75585077eb6d..c7554f5b9fb6 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -128,7 +128,13 @@ static unsigned long quarantine_batch_size; =20 static struct kmem_cache *qlink_to_cache(struct qlist_node *qlink) { - return virt_to_slab(qlink)->slab_cache; + struct slab *folio_slab =3D virt_to_slab(qlink); + + if (!folio_slab) { + pr_warn("The address %p does not belong to a slab", qlink); + return NULL; + } + return folio_slab->slab_cache; } =20 static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *= cache) --=20 2.36.1