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=-3.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 BB9B6C11F65 for ; Wed, 30 Jun 2021 17:21:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 978BB61490 for ; Wed, 30 Jun 2021 17:21:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232636AbhF3RX4 (ORCPT ); Wed, 30 Jun 2021 13:23:56 -0400 Received: from mail-il1-f198.google.com ([209.85.166.198]:51149 "EHLO mail-il1-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229852AbhF3RXz (ORCPT ); Wed, 30 Jun 2021 13:23:55 -0400 Received: by mail-il1-f198.google.com with SMTP id f7-20020a92c7a70000b02901ee10b89a7fso2380161ilk.17 for ; Wed, 30 Jun 2021 10:21:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=0MCROCOJFuzpUd/PNOloy1xDKZzGHt5w9gFeLFd1IOM=; b=W0ncuMgmvhoOfXBTOWOyU0WlG+BrEKJB9QdAKPDKT4gc99p0R+aMPTLG7JorikffwX 17hL+t1HQhQM6O9LuRG/m2mb7A5z1wnBTaTw/pTMHh+v6Hxpv755gQvIq97GsJNPPOGU xu5kYwcxrMIi+EIKp4IGTVs/3PzrXRQQxUMnke5/yn1lkek4jZ9VxZ7g7QkhVM19M4vS orE1rYoa+We9B8CF+8bgjGw1uEFabIC7iX5l3iojHZfs6Lm+F9CKgS33F0k0iz+mQyzy OO01hM88Y3hGUOC3LPCwTNYYOHAXqCWRGwtM/yMQ81yAKJW7hZtR46BYGN4Um6xz1OVD s2sQ== X-Gm-Message-State: AOAM532n7LIMkVGCrZS/TWpb9FENMIALiW4+k8VWbVNG8JWHsoQlrkLx O0RdCXizT/Q4cKSXNCQK5PgreTq5TI26HM3M5SNtkMvvkfSp X-Google-Smtp-Source: ABdhPJzYA1+QCIsIve+FBZJCBngYTJw85MK7zyuRBr8hmo/vLdtgEZv6VtqWFGgcyA+ycQqUFdC9tFWuvAbOjkcPeMgMomGcDIjq MIME-Version: 1.0 X-Received: by 2002:a5e:8208:: with SMTP id l8mr8632803iom.197.1625073686435; Wed, 30 Jun 2021 10:21:26 -0700 (PDT) Date: Wed, 30 Jun 2021 10:21:26 -0700 In-Reply-To: <00000000000002b41905be665238@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000d05b3805c5fef3ca@google.com> Subject: Re: [syzbot] possible deadlock in vmci_qp_broker_detach From: syzbot To: alex.dewar90@gmail.com, arnd@arndb.de, gregkh@linuxfoundation.org, hdanton@sina.com, jhansen@vmware.com, linux-kernel@vger.kernel.org, snovitoll@gmail.com, syzkaller-bugs@googlegroups.com, vdasa@vmware.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: a1f92694 Add linux-next specific files for 20210518 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=14cf5118300000 kernel config: https://syzkaller.appspot.com/x/.config?x=d612e75ffd53a6d3 dashboard link: https://syzkaller.appspot.com/bug?extid=44e40ac2cfe68e8ce207 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15dae18c300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14c680e2300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+44e40ac2cfe68e8ce207@syzkaller.appspotmail.com ============================================ WARNING: possible recursive locking detected 5.13.0-rc2-next-20210518-syzkaller #0 Not tainted -------------------------------------------- syz-executor723/9333 is trying to acquire lock: ffffffff8cc8b5f8 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 but task is already holding lock: ffffffff8cc8b5f8 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(qp_broker_list.mutex); lock(qp_broker_list.mutex); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor723/9333: #0: ffffffff8cc8b5f8 (qp_broker_list.mutex){+.+.}-{3:3}, at: vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 stack backtrace: CPU: 0 PID: 9333 Comm: syz-executor723 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x13e/0x1d6 lib/dump_stack.c:129 print_deadlock_bug kernel/locking/lockdep.c:2831 [inline] check_deadlock kernel/locking/lockdep.c:2874 [inline] validate_chain kernel/locking/lockdep.c:3663 [inline] __lock_acquire.cold+0x22f/0x3b4 kernel/locking/lockdep.c:4902 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477 __mutex_lock_common kernel/locking/mutex.c:949 [inline] __mutex_lock+0x139/0x1120 kernel/locking/mutex.c:1096 vmci_qp_broker_detach+0x147/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2093 ctx_free_ctx+0x4cc/0xd30 drivers/misc/vmw_vmci/vmci_context.c:444 kref_put include/linux/kref.h:65 [inline] vmci_ctx_put drivers/misc/vmw_vmci/vmci_context.c:497 [inline] vmci_ctx_enqueue_datagram+0x4dc/0x620 drivers/misc/vmw_vmci/vmci_context.c:360 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:275 [inline] vmci_datagram_dispatch+0x39b/0xb50 drivers/misc/vmw_vmci/vmci_datagram.c:339 qp_notify_peer+0x182/0x260 drivers/misc/vmw_vmci/vmci_queue_pair.c:1479 vmci_qp_broker_detach+0xa09/0x11b0 drivers/misc/vmw_vmci/vmci_queue_pair.c:2186 ctx_free_ctx+0x4cc/0xd30 drivers/misc/vmw_vmci/vmci_context.c:444 kref_put include/linux/kref.h:65 [inline] vmci_ctx_put drivers/misc/vmw_vmci/vmci_context.c:497 [inline] vmci_ctx_destroy+0x169/0x1d0 drivers/misc/vmw_vmci/vmci_context.c:195 vmci_host_close+0x116/0x1a0 drivers/misc/vmw_vmci/vmci_host.c:143 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x26f/0x280 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x3e/0xb0 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x445ac9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe38cec92f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000124 RAX: 0000000000000005 RBX: 00000000004ca420 RCX: 0000000000445ac9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00000000004ca42c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049a074 R13: 65732f636f72702f R14: 636d762f7665642f R15: 00000000004ca428