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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BDBFC5AD49 for ; Wed, 28 May 2025 01:58:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 71FE06B007B; Tue, 27 May 2025 21:58:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6AA9D6B0082; Tue, 27 May 2025 21:58:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 573CD6B0083; Tue, 27 May 2025 21:58:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 341726B007B for ; Tue, 27 May 2025 21:58:42 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9F7B8845C2 for ; Wed, 28 May 2025 01:58:41 +0000 (UTC) X-FDA: 83490657642.15.C804E70 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf30.hostedemail.com (Postfix) with ESMTP id 5A00D80004 for ; Wed, 28 May 2025 01:58:38 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf30.hostedemail.com: domain of tujinjiang@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=tujinjiang@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748397520; h=from:from:sender: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: references; bh=9taDn37tkFwvwhAax7VYN1/mBOn2m/9OaPKaQmr3Ug4=; b=TbfmPOYXGGFVWOd76TtB4zbe9DWA5AVYRTZerCk55cgeqNKaj1NubfWfs8fpT3Jtwe0hFL xffkgUDgTpIliXWDu1DRTfQnpEiuHEceaHCcb5FaymKnIyzCvFTktNTsxJ+wRxmcKDNUJn 99LSSVfctc4hT3DP9Ccs+olL5PVmkgk= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf30.hostedemail.com: domain of tujinjiang@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=tujinjiang@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1748397520; a=rsa-sha256; cv=none; b=YQNl1Byhb3SqetlLhV78YL3e4vqymqCRqJ3nJxnCYWv26sdpIDcyvtXzmOcVZGXL5siJ1d uHoyesdTGZaaeg0WpUMwHZg74ukcZrdlwvbDcseCInJvn3D4yxiiB+k/vuMbwSj5M+yBS2 lG2+gEfatP2v+O7Gr8CKLrFvvibMkUI= Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4b6XcN60xnzRjtY; Wed, 28 May 2025 09:54:28 +0800 (CST) Received: from kwepemo200002.china.huawei.com (unknown [7.202.195.209]) by mail.maildlp.com (Postfix) with ESMTPS id 9CAB6180B61; Wed, 28 May 2025 09:58:35 +0800 (CST) Received: from huawei.com (10.175.124.71) by kwepemo200002.china.huawei.com (7.202.195.209) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 28 May 2025 09:58:34 +0800 From: Jinjiang Tu To: , , , , , , , CC: , , Subject: [PATCH] mm: fix COW mapping handing in generic_access_phys Date: Wed, 28 May 2025 09:56:17 +0800 Message-ID: <20250528015617.302681-1-tujinjiang@huawei.com> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.175.124.71] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemo200002.china.huawei.com (7.202.195.209) X-Rspamd-Queue-Id: 5A00D80004 X-Stat-Signature: qt9ciywo1q3isrsaxycm78zqfbofkjm4 X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1748397518-533392 X-HE-Meta: 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 PLsRMDXx 4xAVSTT+qxgplJqHOmxZoGme1KmI7iS3jz3NJ7VlzyrUXSWzkiZ7S4TBRuVS4EKTOeZo+o42a+RtwdAjIPgwwBL3o2pugyJVyQsKXvcuZPNfbLsryuSgZ2hbo7kCdvpdcF0r0VsDbSsDE7d6YkMH16o7YxYl6z1qhxJw1yltl8BxetqlFPYgpltcoiVAgzdtcsTV/HrO8mWMKcP6MzbnPoThnV26HYD3AF1WRjkaU3lEgQrOgQUR8a6riA2uf07Q7V0BOMrkYOnai51/D/5nvJRTJ2tJjhY7EYWCiiPeTirui33Y= 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: Syzkaller reports a below BUG: ioremap on RAM at 0x0000000022727000 - 0x0000000022727fff WARNING: CPU: 3 PID: 3609 at arch/x86/mm/ioremap.c:216 __ioremap_caller+0x644/0x7f0 arch/x86/mm/ioremap.c:216 Modules linked in: CPU: 3 PID: 3609 Comm: syz.2.577 Not tainted 6.6.0+ #63 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:__ioremap_caller+0x644/0x7f0 arch/x86/mm/ioremap.c:216 Call Trace: generic_access_phys+0x241/0x480 mm/memory.c:6458 __access_remote_vm+0x6af/0x970 mm/memory.c:6535 access_process_vm+0x53/0x80 mm/memory.c:6600 get_cmdline+0x192/0x380 mm/util.c:1041 audit_log_proctitle kernel/auditsc.c:1620 [inline] audit_log_exit+0x1424/0x18c0 kernel/auditsc.c:1811 __audit_syscall_exit+0x252/0x2f0 kernel/auditsc.c:2079 audit_syscall_exit include/linux/audit.h:356 [inline] syscall_exit_work+0x10f/0x130 kernel/entry/common.c:166 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x10/0x1e0 kernel/entry/common.c:218 do_syscall_64+0x66/0x110 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x78/0xe2 The /dev/mem is mapped with COW mapping, and mremap at the mm->args_start. The special pfn mapping is replaced by anon folios due to COW. generic_access_phys() is supposed to handle iomem, instead of RAM pfn, thus trigger a WARN_ON. Similar to commit 04c35ab3bdae ("x86/mm/pat: fix VM_PAT handling in COW mappings"). check if the pte is special to reject Cowed anon folios. Signed-off-by: Jinjiang Tu --- mm/memory.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 49199410805c..e1dac84536ee 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6840,6 +6840,13 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, retry: if (follow_pfnmap_start(&args)) return -EINVAL; + + /* Never return PFNs of anon folios in COW mappings. */ + if (!args.special) { + follow_pfnmap_end(&args); + return -EINVAL; + } + prot = args.pgprot; phys_addr = (resource_size_t)args.pfn << PAGE_SHIFT; writable = args.writable; -- 2.43.0