From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15D38205507 for ; Fri, 10 Jan 2025 16:35:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736526932; cv=none; b=ND4yhcRvRUYnCCSOyUFXPG06fh/asCj+Zt16X/39HZOuEB4rtf84KuKZc6OWtN1tGkheD8FEXOOwK9dCfe6u8dTnaBtEbszksPjBHVF/CEu6Eg6gT6Guoinnch4H5+X6/QV/bKGiqFuWvb5xmQAOE47eQRYsRLWHnRGd4Ja8hHA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736526932; c=relaxed/simple; bh=pqot1crnfTtp/JUiMqWbUf239xsySN8Md9ERxlY1n2k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rG0CAuxT7P38EkD1vBPBpnGbKrloqe/If987GkQLeIXLesvL2IybfFSlI9k/M6y4Mw7350qjeMaXvF1tlNEx+josPqWgmxoJTZ4nQZr1CCiG/C5Pshk9xeWcr9u6nTrDm+PTeSXlzm0BpIx2l7+9H1l0IbUf3vE92K6A2Labcxs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Fa0hsVsl; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fa0hsVsl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1736526929; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=ZHBvTjtVEfUgiHMzO3uoRa4mB68/VeNvJdCapSbPe4E=; b=Fa0hsVsl+OVIlsqwTVUtRrGf9wzUqz/NOLmwZdNDaxMU2Dqw5pZ+i1nJxfYWmf3kfTlkah OIOYmfTS9avaoluJWz+sfz33rK6MgCSNWwt0XwYP2Qo/i6m83KlQ7PzUDoQJO/alY65oSi StpG+DXXJcOz0qLxFeL1z93nNW6qKwY= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-632-CrsmEXPFNw-l1b9sFqXVGA-1; Fri, 10 Jan 2025 11:35:28 -0500 X-MC-Unique: CrsmEXPFNw-l1b9sFqXVGA-1 X-Mimecast-MFC-AGG-ID: CrsmEXPFNw-l1b9sFqXVGA Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-385d52591d6so1019377f8f.1 for ; Fri, 10 Jan 2025 08:35:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736526927; x=1737131727; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=ZHBvTjtVEfUgiHMzO3uoRa4mB68/VeNvJdCapSbPe4E=; b=PpZQGH4sCNqpQgQFVtSdVaIWciw7qAunSnjyX6tADl+b/d5bIt7fBfEdVyuX7M2UlW ef6oGwCTyKCrE94X2O8SHaYKC21CB97MQH+XsItXho5ZNocxjsf1U8P32wSxAUZSMPOG hpQo8IT/pCItQFxBY0DlbzatgT7haOZrygdqfTA/b+zft84l2m7eLEavw91s0etIa1gp Y2e7h7X9RDx3NAzoC5TYfn9WR+b7ZvCnu9ybMkS3CmZXYR/j3EkTSTq9eulAmGxzzOG5 R2Flb7G7r6TSsykqK1CTxbpGihXV6sedYaQlwafHdnTaA9ShSZeb86j3cZmg5SZKlCRf Fhig== X-Forwarded-Encrypted: i=1; AJvYcCVpV4OH1rgqDcpaMbDyVa0mVZmaCjBNcA+jpR+gwqifm/2RuPIFqds2Xlw+CE7Al4iGwnaHwAWHRPqnQCA=@vger.kernel.org X-Gm-Message-State: AOJu0YxJsQ2keDv/Tg+j4y8YZQbPO1Te7ohZIuo4lF0qYVbX9lMfC/NF 0uhOjo2FKm12w9jgeQrkKzgilIOCK+DAt4uvFKYZPQoJL8g1UVA18ZnFQf6s3Kl1hYMTXPH2KWD iVduY47nJWjA15YdON7xoSO4J3DsUGhgf4ujW/g/9wyA9WgHmAoUP36NtH2aZjQ== X-Gm-Gg: ASbGncuhsHXR9BYxybSUrKDCaahYc7Awg/+khm2ILak8WmlJl3WTnwUSMC2aYNFlu3W xMaig0YZD4sOkIn0P6+A0k9mkj6P5XC14TLTGY/tHsEpun3BRhhME+EfkffLTUECtL+ngtDJxoP MXyaqS1MHoDcQtO1x//ck8hI+hMZLL9+tALD2qRzWY5DYqHD1zEeMC6kR9KxufYtBbHFTrnBWM6 dpstKtgtT1xjaQgVPklVeBv/QFJ3F450iN+2rh7KZV7+OyK6FyqonZE0hlKRuISsFp+fMt8Ra2d MJYHZgUC5UwfcQOxrCyVtaxzndPB+wyKxjTI5BUPIyZ3iAqbwy9amz3nC6OEttj0sqPNEpapO8G nxq4HXtDD X-Received: by 2002:a05:6000:4026:b0:386:3c2f:a3e7 with SMTP id ffacd0b85a97d-38a8b0b7fdcmr6876607f8f.3.1736526927465; Fri, 10 Jan 2025 08:35:27 -0800 (PST) X-Google-Smtp-Source: AGHT+IH4glteLn3Br8mvn1QQrtGtHiay5NjzNQSSPoxR1EFypAWSEigH1RaHMu3w2iSakHWjiOXOEw== X-Received: by 2002:a05:6000:4026:b0:386:3c2f:a3e7 with SMTP id ffacd0b85a97d-38a8b0b7fdcmr6876586f8f.3.1736526927142; Fri, 10 Jan 2025 08:35:27 -0800 (PST) Received: from ?IPV6:2003:cb:c708:e100:4f41:ff29:a59f:8c7a? (p200300cbc708e1004f41ff29a59f8c7a.dip0.t-ipconnect.de. [2003:cb:c708:e100:4f41:ff29:a59f:8c7a]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-436e2dc08bbsm90707445e9.12.2025.01.10.08.35.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 10 Jan 2025 08:35:25 -0800 (PST) Message-ID: Date: Fri, 10 Jan 2025 17:35:25 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [mm?] WARNING in __folio_rmap_sanity_checks (2) To: Hillf Danton , syzbot Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <20241231084108.1146-1-hdanton@sina.com> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20241231084108.1146-1-hdanton@sina.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 31.12.24 09:41, Hillf Danton wrote: > On Fri, 27 Dec 2024 20:56:21 -0800 >> syzbot has found a reproducer for the following issue on: >> >> HEAD commit: 8155b4ef3466 Add linux-next specific files for 20241220 >> git tree: linux-next >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1652fadf980000 > > #syz test > > --- x/mm/filemap.c > +++ y/mm/filemap.c > @@ -3636,6 +3636,10 @@ static vm_fault_t filemap_map_folio_rang > continue; > skip: > if (count) { > + for (unsigned int i = 0; i < count; i++) { > + if (page_folio(page + i) != folio) > + goto out; > + } IIRC, count <= nr_pages. Wouldn't that mean that we somehow pass in nr_pages that already exceeds the given folio+start? When I last looked at this, I was not able to spot the error in the caller :( > set_pte_range(vmf, folio, page, count, addr); > *rss += count; > folio_ref_add(folio, count); > @@ -3658,6 +3662,7 @@ skip: > ret = VM_FAULT_NOPAGE; > } > > +out: > vmf->pte = old_ptep; > > return ret; > @@ -3702,7 +3707,7 @@ vm_fault_t filemap_map_pages(struct vm_f > struct file *file = vma->vm_file; > struct address_space *mapping = file->f_mapping; > pgoff_t file_end, last_pgoff = start_pgoff; > - unsigned long addr; > + unsigned long addr, pmd_end; > XA_STATE(xas, &mapping->i_pages, start_pgoff); > struct folio *folio; > vm_fault_t ret = 0; > @@ -3731,6 +3736,12 @@ vm_fault_t filemap_map_pages(struct vm_f > if (end_pgoff > file_end) > end_pgoff = file_end; > > + /* make vmf->pte[x] valid */ > + pmd_end = ALIGN(addr, PMD_SIZE); > + pmd_end = (pmd_end - addr) >> PAGE_SHIFT; > + if (end_pgoff - start_pgoff > pmd_end) > + end_pgoff = start_pgoff + pmd_end; > + do_fault_around() comments "This way it's easier to guarantee that we don't cross page table boundaries." It does some magic with PTRS_PER_PTE. You're diff here seems to indicate that this is not the case? But it's rather surprising that we see these issues pop up just now in -next. -- Cheers, David / dhildenb