From nobody Fri Oct 3 16:44:17 2025 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 082621A9FB8 for ; Thu, 28 Aug 2025 02:54:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756349702; cv=none; b=VezCPV928FMhlPEGKozqjTlvjkd+TAw/VI3mx8J0eViLTCwDG/d6POtggjcsJGcZoqMJoy9GZPACTBWVlMqKUuHiU8Xwi7LkM8mrxZ6oEHwvUr9R8sh/fOR+i6Ubun9+uoN3EyLd94ceP6e1/Xh5QtrU5s0STIeQ0NAql4M8Kk0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756349702; c=relaxed/simple; bh=jrP5tsn75ZKmWcUJ6IrkqVA2DWJPtaGtNyFjOfvLCd4=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=g4/F/ex1JsEtD+QLKo5Zz0Q254xBhCV0vBVLU5DZLfiJO2jsDiECKnwww5SsHOsuAhJxjZZ82GERo//mrB+Lr+elOCFNrUx0yKFS74MjfjKYDZON/vEq4m1Vo96YhcuKOuXXqmozJQGdZdLLLDE/r9Wtc/MQFXgtlK9POJLcaYE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.234]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4cC5d00hTzz27jHf; Thu, 28 Aug 2025 10:56:04 +0800 (CST) Received: from dggemv706-chm.china.huawei.com (unknown [10.3.19.33]) by mail.maildlp.com (Postfix) with ESMTPS id 5C6AB14025A; Thu, 28 Aug 2025 10:54:57 +0800 (CST) Received: from kwepemq500010.china.huawei.com (7.202.194.235) by dggemv706-chm.china.huawei.com (10.3.19.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 28 Aug 2025 10:54:57 +0800 Received: from huawei.com (10.173.125.236) by kwepemq500010.china.huawei.com (7.202.194.235) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 28 Aug 2025 10:54:56 +0800 From: Miaohe Lin To: CC: , , , , Subject: [PATCH v4] mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory Date: Thu, 28 Aug 2025 10:46:18 +0800 Message-ID: <20250828024618.1744895-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.33.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemq500010.china.huawei.com (7.202.194.235) Content-Type: text/plain; charset="utf-8" When I did memory failure tests, below panic occurs: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) kernel BUG at include/linux/page-flags.h:616! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Call Trace: unpoison_memory+0x2f3/0x590 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xd5/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f0314887 RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 Modules linked in: hwpoison_inject Acked-by: David Hildenbrand Suggested-by: David Hildenbrand ---[ end trace 0000000000000000 ]--- RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffff= ffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- The root cause is that unpoison_memory() tries to check the PG_HWPoison flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is triggered. This can be reproduced by below steps: 1.Offline memory block: echo offline > /sys/devices/system/memory/memory12/state 2.Get offlined memory pfn: page-types -b n -rlN 3.Write pfn to unpoison-pfn echo > /sys/kernel/debug/hwpoison/unpoison-pfn This scene can be identified by pfn_to_online_page() returning NULL. And ZONE_DEVICE pages are never expected, so we can simply fail if pfn_to_online_page() =3D=3D NULL to fix the bug. Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory = to zones until online") Suggested-by: David Hildenbrand Signed-off-by: Miaohe Lin --- v2: Use pfn_to_online_page per David. Thanks. v3: Simply fail if pfn_to_online_page() =3D=3D NULL per David. Thanks. v4: Add Fixes tag and remove pfn_valid check per David. Thanks. --- mm/memory-failure.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index c15ffee7d32b..4af8875b07b6 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2569,10 +2569,9 @@ int unpoison_memory(unsigned long pfn) static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); =20 - if (!pfn_valid(pfn)) - return -ENXIO; - - p =3D pfn_to_page(pfn); + p =3D pfn_to_online_page(pfn); + if (!p) + return -EIO; folio =3D page_folio(p); =20 mutex_lock(&mf_mutex); --=20 2.33.0