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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49C09C04AB6 for ; Tue, 28 May 2019 08:35:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29856208CB for ; Tue, 28 May 2019 08:35:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726844AbfE1IfG (ORCPT ); Tue, 28 May 2019 04:35:06 -0400 Received: from relay.sw.ru ([185.231.240.75]:44080 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbfE1IfF (ORCPT ); Tue, 28 May 2019 04:35:05 -0400 Received: from [172.16.25.169] by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1hVXZU-000124-DK; Tue, 28 May 2019 11:35:00 +0300 Subject: Re: [PATCH] list_lru: fix memory leak in __memcg_init_list_lru_node To: Shakeel Butt , Vladimir Davydov , Michal Hocko , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, syzbot+f90a420dfe2b1b03cb2c@syzkaller.appspotmail.com References: <20190528043202.99980-1-shakeelb@google.com> From: Kirill Tkhai Message-ID: <6ed45785-4b5b-83f9-6487-6c4142fe22ac@virtuozzo.com> Date: Tue, 28 May 2019 11:34:59 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190528043202.99980-1-shakeelb@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28.05.2019 07:32, Shakeel Butt wrote: > Syzbot reported following memory leak: > > ffffffffda RBX: 0000000000000003 RCX: 0000000000441f79 > BUG: memory leak > unreferenced object 0xffff888114f26040 (size 32): > comm "syz-executor626", pid 7056, jiffies 4294948701 (age 39.410s) > hex dump (first 32 bytes): > 40 60 f2 14 81 88 ff ff 40 60 f2 14 81 88 ff ff @`......@`...... > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<0000000018f36b56>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] > [<0000000018f36b56>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<0000000018f36b56>] slab_alloc mm/slab.c:3326 [inline] > [<0000000018f36b56>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<0000000055b9a1a5>] kmalloc include/linux/slab.h:547 [inline] > [<0000000055b9a1a5>] __memcg_init_list_lru_node+0x58/0xf0 mm/list_lru.c:352 > [<000000001356631d>] memcg_init_list_lru_node mm/list_lru.c:375 [inline] > [<000000001356631d>] memcg_init_list_lru mm/list_lru.c:459 [inline] > [<000000001356631d>] __list_lru_init+0x193/0x2a0 mm/list_lru.c:626 > [<00000000ce062da3>] alloc_super+0x2e0/0x310 fs/super.c:269 > [<000000009023adcf>] sget_userns+0x94/0x2a0 fs/super.c:609 > [<0000000052182cd8>] sget+0x8d/0xb0 fs/super.c:660 > [<0000000006c24238>] mount_nodev+0x31/0xb0 fs/super.c:1387 > [<0000000006016a76>] fuse_mount+0x2d/0x40 fs/fuse/inode.c:1236 > [<000000009a61ec1d>] legacy_get_tree+0x27/0x80 fs/fs_context.c:661 > [<0000000096cd9ef8>] vfs_get_tree+0x2e/0x120 fs/super.c:1476 > [<000000005b8f472d>] do_new_mount fs/namespace.c:2790 [inline] > [<000000005b8f472d>] do_mount+0x932/0xc50 fs/namespace.c:3110 > [<00000000afb009b4>] ksys_mount+0xab/0x120 fs/namespace.c:3319 > [<0000000018f8c8ee>] __do_sys_mount fs/namespace.c:3333 [inline] > [<0000000018f8c8ee>] __se_sys_mount fs/namespace.c:3330 [inline] > [<0000000018f8c8ee>] __x64_sys_mount+0x26/0x30 fs/namespace.c:3330 > [<00000000f42066da>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<0000000043d74ca0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > This is a simple off by one bug on the error path. > > Reported-by: syzbot+f90a420dfe2b1b03cb2c@syzkaller.appspotmail.com > Signed-off-by: Shakeel Butt Reviewed-by: Kirill Tkhai > --- > mm/list_lru.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/list_lru.c b/mm/list_lru.c > index 0bdf3152735e..92870be4a322 100644 > --- a/mm/list_lru.c > +++ b/mm/list_lru.c > @@ -358,7 +358,7 @@ static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus, > } > return 0; > fail: > - __memcg_destroy_list_lru_node(memcg_lrus, begin, i - 1); > + __memcg_destroy_list_lru_node(memcg_lrus, begin, i); > return -ENOMEM; > } > >