From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAE54C56201 for ; Wed, 11 Nov 2020 19:27:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5C0BB208C3 for ; Wed, 11 Nov 2020 19:27:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h4IYp7gb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C0BB208C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B00276B0036; Wed, 11 Nov 2020 14:27:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AAEBC6B005D; Wed, 11 Nov 2020 14:27:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 980AA6B0068; Wed, 11 Nov 2020 14:27:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0194.hostedemail.com [216.40.44.194]) by kanga.kvack.org (Postfix) with ESMTP id 6A74C6B0036 for ; Wed, 11 Nov 2020 14:27:00 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 1AF28180AD802 for ; Wed, 11 Nov 2020 19:27:00 +0000 (UTC) X-FDA: 77473120200.16.bikes73_5c027d727300 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id E7C6F100E690C for ; Wed, 11 Nov 2020 19:26:59 +0000 (UTC) X-HE-Tag: bikes73_5c027d727300 X-Filterd-Recvd-Size: 4144 Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Nov 2020 19:26:59 +0000 (UTC) Received: by mail-ed1-f50.google.com with SMTP id t9so3520328edq.8 for ; Wed, 11 Nov 2020 11:26:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bMLjI/601C9OPQNA+LqIrQMDDAlDxJCIUFBAsIL0uwg=; b=h4IYp7gble1Q0vh1fdFK2sJupdlvWR5d0OIhAe6P5UgZJy1fZvGi94CO54o5vE13t/ r77GkOUsUtPP7qmQU+ZVPii+N188Lr97JOAz2L06eFxv5YO3bkrlZH0zZwhVKtbaDoly GDpwZ72xniQ9c4hqmscXHQ3XMD1sA2rE0KqrGNEIMhMA8WS9pTHabamdU/43SqZ4gS0W vcZzR8O6+5nR5DCuN6PMtYFjdI+IRul12llL3HYSlxq9j6n1/W25a5jrKDWQW2s4F/Yb 8Uj2ANCjF9fFpjwS0T2gF5O4bDXVxbXUSHTzQugsr1zhdqb+NGdU5UBXfWqkSLpxcQ89 nz2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bMLjI/601C9OPQNA+LqIrQMDDAlDxJCIUFBAsIL0uwg=; b=qcNcVBqUFdXUERYV+ZOTcaC34das5niLsksX8KrZFY6exciyd2TL5MqlNbUvAA8w8s PKB7bJw2dPBJuAN1c9IOw9mGdyBYQcF6YNB/XNjlkGT4w/yAPEybpk22KAoKcIGIiUgv Ljl3Nnqs2qgMgAXU5pFJEJlE3Uj/qR+OaLkjYbwR9aS5g6wIrXctrpFFcv+J/+d4Pih6 V4NzY9goZumeUOpHt97m+MzU2O/rlUWB6sS8NzWu4u+U1TQrVo+3iJLIKk/2ztNwDbpL HGQRyZsLsUAK2JkOVZzOgMvwIu1r76+GjfgwQ9mF02zPvGZjXLCRuJNtDr72L0w3eOfR ZPqA== X-Gm-Message-State: AOAM531lc2p9Ndg9WT0pu+C4jC9WGCi45SBu2YsEVRtHnEk6UNtBZbyO MRXEX4HwYRdcc4Sa/aRXxvckeUPgR8LWZaJuLJw= X-Google-Smtp-Source: ABdhPJxwX1ejaYw2R2D2HuKudT6+qpe+Dp+KKAb0PZFN9O7AJvhP8s8QpEfz4dxZf82tDXK/9t8ojLT7bvfOi4z15kE= X-Received: by 2002:a50:eb0a:: with SMTP id y10mr1199265edp.342.1605122818353; Wed, 11 Nov 2020 11:26:58 -0800 (PST) MIME-Version: 1.0 References: <000000000000fe575905b3cff92c@google.com> In-Reply-To: From: Lorenzo Stoakes Date: Wed, 11 Nov 2020 19:26:47 +0000 Message-ID: Subject: Re: linux-next boot error: BUG: unable to handle kernel NULL pointer dereference in mempool_init_node To: Andrey Konovalov Cc: Qian Cai , syzbot , Andrew Morton , LKML , Linux Memory Management List , Linux-Next Mailing List , Stephen Rothwell , syzkaller-bugs , Dmitry Vyukov , Alexander Potapenko , Marco Elver Content-Type: text/plain; charset="UTF-8" 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: On Wed, 11 Nov 2020 at 17:44, Andrey Konovalov wrote: > I'll try to reproduce this and figure out the issue. Thanks for letting us know! I hope you don't mind me diving in here, I was taking a look just now and managed to reproduce this locally - I bisected the issue to 105397399 ("kasan: simplify kasan_poison_kfree"). If I stick a simple check in as below it fixes the issue, so I'm guessing something is violating the assumptions in 105397399? diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 7a94cebc0324..16163159a017 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -387,6 +387,11 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip) struct page *page; page = virt_to_head_page(ptr); + + if (!PageSlab(page)) { + return; + } + ____kasan_slab_free(page->slab_cache, ptr, ip, false); } -- Lorenzo Stoakes https://ljs.io