From patchwork Fri Oct 28 07:37:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zetao X-Patchwork-Id: 13023143 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 6F77CECAAA1 for ; Fri, 28 Oct 2022 06:48:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DA37E6B0072; Fri, 28 Oct 2022 02:48:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D54AA6B0073; Fri, 28 Oct 2022 02:48:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C41EA6B0074; Fri, 28 Oct 2022 02:48:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B8BB46B0072 for ; Fri, 28 Oct 2022 02:48:43 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 8328FC1183 for ; Fri, 28 Oct 2022 06:48:43 +0000 (UTC) X-FDA: 80069430126.05.0612F9C Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf06.hostedemail.com (Postfix) with ESMTP id 3D8B818001B for ; Fri, 28 Oct 2022 06:48:40 +0000 (UTC) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MzCj13RstzpWHq; Fri, 28 Oct 2022 14:45:09 +0800 (CST) Received: from huawei.com (10.67.175.21) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 28 Oct 2022 14:48:36 +0800 From: Li Zetao To: CC: , , , , , , , Subject: [PATCH v2] mm/mmap: Fix memory leak in mmap_region() Date: Fri, 28 Oct 2022 15:37:17 +0800 Message-ID: <20221028073717.1179380-1-lizetao1@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221027073029.dyo2p2kearlutizq@revolver> References: <20221027073029.dyo2p2kearlutizq@revolver> MIME-Version: 1.0 X-Originating-IP: [10.67.175.21] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of lizetao1@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=lizetao1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666939722; a=rsa-sha256; cv=none; b=KDLQGm+XkS9N/v4Lq8C+WGykgsK6L2gGKiReL1mep0etjYqVswZuSHlNduKwL4B8QYFSEV jqr2pOdwsp1ARAwBgYLn7CTLDB01+ATtdgOz0Xe4/LTMCQUDSAkM6/okIroS8XvahyJIct IGhh3RjSFlJWSjF6SM2RpHuFJw6Wmig= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666939722; 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:in-reply-to:references:references; bh=6TH8Z9A8O4HDvnCp8HYaIQuH6GaTzFXq5dgeOFEF/dI=; b=SuOmp2NEF5lbihrGxagBQFn2ghO88JPqmnMGqmeiVwQ+h93csztTHzYTytCtiPB1204ifU nHdReB8FhdcYAqHtv5AOc2pSVDLoz76Uw2u+ZI1QhgPvjEqZSCj+D4aQip2WklLvteMRpq ZPlNmhD0LRC4+CT73JEhGnhCDywaRDQ= X-Rspam-User: X-Rspamd-Queue-Id: 3D8B818001B Authentication-Results: imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of lizetao1@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=lizetao1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Stat-Signature: 4g4d637x8g3q7mts3xqs53s6jsz775cu X-Rspamd-Server: rspam10 X-HE-Tag: 1666939720-693589 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: There is a memory leak reported by kmemleak: unreferenced object 0xffff88817231ce40 (size 224): comm "mount.cifs", pid 19308, jiffies 4295917571 (age 405.880s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 60 c0 b2 00 81 88 ff ff 98 83 01 42 81 88 ff ff `..........B.... backtrace: [] __alloc_file+0x21/0x250 [] alloc_empty_file+0x41/0xf0 [] alloc_file+0x59/0x710 [] alloc_file_pseudo+0x154/0x210 [] __shmem_file_setup+0xff/0x2a0 [] shmem_zero_setup+0x8d/0x160 [] mmap_region+0x1075/0x19d0 [] do_mmap+0x727/0x1110 [] vm_mmap_pgoff+0x112/0x1e0 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 The root cause was traced to an error handing path in mmap_region() when arch_validate_flags() or mas_preallocate() fails. In the shared anonymous mapping sence, vma will be setuped and mapped with a new shared anonymous file via shmem_zero_setup(). So in this case, the file resource needs to be released. Fix it by calling fput(vma->vm_file) and unmap_region() when arch_validate_flags() or mas_preallocate() returns an error in the shared anonymous mapping sence. Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree") Fixes: c462ac288f2c ("mm: Introduce arch_validate_flags()") Signed-off-by: Li Zetao Reviewed-by: Liam R. Howlett --- v1 was posted at: https://lore.kernel.org/all/20221027025837.136492-1-lizetao1@huawei.com/ v1 -> v2: Drop the new goto label, and jump to unmap_and_free_vma "if (vma->vm_file)" mm/mmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/mmap.c b/mm/mmap.c index e270057ed04e..77846d8cf9d4 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2674,6 +2674,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, error = -EINVAL; if (file) goto close_and_free_vma; + else if (vma->vm_file) + goto unmap_and_free_vma; else goto free_vma; } @@ -2682,6 +2684,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, error = -ENOMEM; if (file) goto close_and_free_vma; + else if (vma->vm_file) + goto unmap_and_free_vma; else goto free_vma; } @@ -2751,7 +2755,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, /* Undo any partial mapping done by a device driver. */ unmap_region(mm, mas.tree, vma, prev, next, vma->vm_start, vma->vm_end); - if (vm_flags & VM_SHARED) + if (file && (vm_flags & VM_SHARED)) mapping_unmap_writable(file->f_mapping); free_vma: vm_area_free(vma);