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b=sebSfXbptLEqXWM7aQrpcCaIOcv3oK39oeD+G6DDM53sXrb4q6jou6B+tOWd+o5uO CNe6CCCZxU6vyQbt/XH5XA3ECiQEriD8EfH+cLIQCZuoYSntC7Xw7BVB0hxnI23uaW XoG9mqcwLiUrNW9sW9XChNnSau7mq0gejdVDDJeoeCQpOD1taQhqlNrCV2WvqV/8fq PlkcqE8mA4e1cS9JZQ3tlvdGu22rue4yVeztUdc/7diyhxp1bhihl/ls7seSNtgQBR V5OveKB2WZ7SR/v/9p0uJUYR9SEZuia2qcrD5FRo34RaYhVW/mBo6FZl+xZrJpoaeM u0ORBTA62F0ug== Message-ID: <1db245a8-f9ab-42e4-8cc6-cc7562961921@kernel.org> Date: Wed, 4 Feb 2026 18:15:38 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: WARNING in memory_failure() at include/linux/huge_mm.h:635 triggered From: "David Hildenbrand (arm)" To: =?UTF-8?B?5piv5Y+C5beu?= , "linux-mm@kvack.org" Cc: "linmiaohe@huawei.com" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , Zi Yan , Matthew Wilcox References: Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 6A660180006 X-Stat-Signature: b4n5d8xmg35r4wfa81eg7jqdp4unrgkz X-HE-Tag: 1770225343-48426 X-HE-Meta: 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 /r3gNcOs 7Es0K9D3Qo4/SrtoFVDQNqbg6AgfV/cuEqperHjc8K//EFzuyyTnhPme8MSYP9R6XczsLNSGt43eMl1CN0t3TxtVWWTiPcqAEEvgDjBblXXHK46sr8isFIA8sxSSTfCPj788J4AxqDsiAY/6PwO5o52KDmDXaMDQB4qXge5FhrcbS/R5BzX3OUcEv/yZjsW2P5JGZkL/Myc2j+YEalGoN+Fex7aTjrmcD9Vjemsy97YGSoMQzY2T/YOPy8M3u6ShEw7HoPqVOi+VWVF/GVfu+7gcGYBmjoXP1ShwzN+1rP7ycUXdmN8f2PPFmzkyHp9WBDqr5fIaCV509nu29Xw+bde2tGKEKnyWjZDFYq1umgRmqMxCARTlmGtFWTCoK49TLN/4qq8ebmQh2+00= 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: List-Subscribe: List-Unsubscribe: On 2/4/26 18:12, David Hildenbrand (arm) wrote: > On 2/4/26 13:49, 是参差 wrote: >> Hi, >> I’m reporting a reproducible WARNING triggered in the hwpoison / >> memory_failure path when injecting a hardware-poison event via >> madvise(MADV_HWPOISON). >> >> The warning is triggered by a syzkaller C reproducer that: >> maps a file-backed region with MAP_FIXED, touches related VMAs, and then >> calls madvise() with MADV_HWPOISON over a large range. >> The kernel reports a VM_WARN_ON_ONCE_FOLIO(1) from >> memory_failure() and points to include/linux/huge_mm.h:635, suggesting >> an unexpected folio/page state encountered while handling a poisoned >> compound/huge folio. >> >> The target page appears to be a compound head page (order:3) already >> marked hwpoison. memory_failure() seems to reach a branch that >> unconditionally warns (VM_WARN_ON_ONCE_FOLIO(1) at include/linux/ >> huge_mm.h:635), which usually indicates an “unreachable”/unexpected >> folio type or state transition in the huge/compound folio handling >> logic during hwpoison processing. >> >> This looks like a kernel-side invariant violation rather than a pure >> userspace misuse, since the warning is emitted from an unconditional >> VM_WARN_ON_ONCE_FOLIO(1) site. >> >> Reproducer: >> C reproducer: https://pastebin.com/raw/UxennX2B >> console output: https://pastebin.com/raw/wrhKRwZY >> kernel config: https://pastebin.com/raw/dP93yBLn >> >> Kernel: >> >> HEAD commit: 63804fed149a6750ffd28610c5c1c98cce6bd377 >> >>   git tree: torvalds/linux >> >> kernel version: 6.19.0-rc7  (QEMU Ubuntu 24.10) > > @Zi Yan, this is weird. > > We run into the VM_WARN_ON_ONCE_FOLIO(1, folio); in min_order_for_split(), > which is only active with !CONFIG_TRANSPARENT_HUGEPAGE. > > But how do we get a large folio in that case? folio_test_large(folio) > succeeded. > > I think we rules out hugetlb before in that function. > > > Looking into the full console output, this is an order-3 folio (fully > mapped). > > How do we end up with a large folio here? I am only aware of that > happening when something would > allocate an order-3 compound page (not a folio) and map it into the page > tables. Yes, that > is nasty and can still happen, not sure yet though whether that is > really what the reproducer > triggers. Looking again, mapping:0000000000000000 index:0xffff88800fe2e600 At least mapping==0 could indicate a non-folio thing. -- Cheers, David