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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F7CDC433EF for ; Sun, 10 Jul 2022 06:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229470AbiGJGfd (ORCPT ); Sun, 10 Jul 2022 02:35:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229450AbiGJGfc (ORCPT ); Sun, 10 Jul 2022 02:35:32 -0400 Received: from mail-il1-f197.google.com (mail-il1-f197.google.com [209.85.166.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE91DB49D for ; Sat, 9 Jul 2022 23:35:29 -0700 (PDT) Received: by mail-il1-f197.google.com with SMTP id i8-20020a056e020d8800b002d931252904so1586435ilj.23 for ; Sat, 09 Jul 2022 23:35:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=PYHrSxK6D4urlBuvXCPCwYEsgi3h0uafRu68kLSJB5k=; b=Xd2JBEDQUlxFM1x1vzUk6hNa+rHCLOvBbSDkYzURyrJ+3mlTBvCaiPkMfXSZZ8dWdF xiHF9W+FwzuflNKyGmJ0ERdPljObjYWsfjyRvzhMzFrrRutf8TatVMUtuMCNW2GUrvJY g4wVwg250TYrS6X8jrERKBz3du5PQPMxguWTVMTcsNBck1++QgLvoCALZBRppxxwVbh4 Zpnqz9Yqr5QUfbTb1bXx/w5uJlugnZSfmuJcVOBqaV3PNDa7irDQa+ms5gD4cy+WGMGj 7uJqlTC3dwm10/nWlOq8VDd3MpaH4QK10TIumGpyNdqEFYarj4Go/AYutMtxaaZRPGjm ao6g== X-Gm-Message-State: AJIora/I1HQ/aArXXJCoJJWXfpiyFFtRIxMCtSwxMQ1hAPKmzzzK3IRc GeK/N6hmDLhkMefXXTiprcfy1Na+wBbC10KbpRwEsaqvEHOW X-Google-Smtp-Source: AGRyM1twZEhViWdO/vM1Cu90saFZ815s7wDAcbYndnheUR22BGcMgDoCynoSySfj6l/8ez4PCtvU/lsVDFZg6eb7j05U7pMkHWRY MIME-Version: 1.0 X-Received: by 2002:a05:6e02:194c:b0:2dc:3f21:63d9 with SMTP id x12-20020a056e02194c00b002dc3f2163d9mr6786632ilu.104.1657434929234; Sat, 09 Jul 2022 23:35:29 -0700 (PDT) Date: Sat, 09 Jul 2022 23:35:29 -0700 In-Reply-To: <00000000000081366905da43b67d@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000320b7e05e36da4a0@google.com> Subject: Re: [syzbot] INFO: task hung in io_uring_del_tctx_node (2) From: syzbot To: asml.silence@gmail.com, axboe@kernel.dk, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: cb71b93c2dc3 Add linux-next specific files for 20220628 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1779602c080000 kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb dashboard link: https://syzkaller.appspot.com/bug?extid=771a9fd5d128e0a5708c compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17011514080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1204baa2080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+771a9fd5d128e0a5708c@syzkaller.appspotmail.com INFO: task syz-executor616:3671 blocked for more than 143 seconds. Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor616 state:D stack:27536 pid: 3671 ppid: 3600 flags:0x00104004 Call Trace: context_switch kernel/sched/core.c:5184 [inline] __schedule+0xa09/0x4f10 kernel/sched/core.c:6496 schedule+0xd2/0x1f0 kernel/sched/core.c:6568 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6627 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa70/0x1350 kernel/locking/mutex.c:747 io_uring_del_tctx_node+0x110/0x2b6 io_uring/tctx.c:175 io_uring_clean_tctx+0xce/0x174 io_uring/tctx.c:191 io_uring_cancel_generic+0x5aa/0x602 io_uring/io_uring.c:2885 io_uring_files_cancel include/linux/io_uring.h:44 [inline] do_exit+0x4f9/0x29f0 kernel/exit.c:750 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7ff32cbe16f9 RSP: 002b:00007ffcbffc2738 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007ff32cc563f0 RCX: 00007ff32cbe16f9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000004140 R10: 0000000000008011 R11: 0000000000000246 R12: 00007ff32cc563f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8bd864f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8bd861f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8bd87040 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491 2 locks held by getty/3275: #0: ffff88807f2e8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xe50/0x13c0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor616/3671: #0: ffff88807eb3c0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_del_tctx_node+0x110/0x2b6 io_uring/tctx.c:175 5 locks held by iou-sqp-3671/3672: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc18/0xf50 kernel/hung_task.c:369 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3672 Comm: iou-sqp-3671 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:199 Code: 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 29 b8 87 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 <65> 48 8b 14 25 80 6f 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 RSP: 0018:ffffc9000313f650 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffff88813fffc320 RCX: 0000000000000000 RDX: ffff8880220a8000 RSI: ffffffff81a97d33 RDI: 0000000000000004 RBP: 0000000000000004 R08: 0000000000000004 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88813fffa000 R14: ffffc9000313f7e0 R15: dffffc0000000000 FS: 000055555676a300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff32cc59370 CR3: 0000000024fc8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: zonelist_zone_idx include/linux/mmzone.h:1160 [inline] next_zones_zonelist include/linux/mmzone.h:1191 [inline] shrink_zones mm/vmscan.c:3474 [inline] do_try_to_free_pages+0x403/0x16f0 mm/vmscan.c:3590 try_to_free_mem_cgroup_pages+0x31e/0x920 mm/vmscan.c:3904 try_charge_memcg+0x500/0x1440 mm/memcontrol.c:2756 obj_cgroup_charge_pages mm/memcontrol.c:3163 [inline] __memcg_kmem_charge_page+0x183/0x3d0 mm/memcontrol.c:3189 __alloc_pages+0x1ef/0x510 mm/page_alloc.c:5523 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2280 io_refill_buffer_cache io_uring/kbuf.c:379 [inline] io_add_buffers io_uring/kbuf.c:405 [inline] io_provide_buffers+0x87d/0xff0 io_uring/kbuf.c:457 io_issue_sqe+0x15e/0xd20 io_uring/io_uring.c:1601 io_queue_sqe io_uring/io_uring.c:1778 [inline] io_submit_sqe io_uring/io_uring.c:2036 [inline] io_submit_sqes+0x9a6/0x1ec0 io_uring/io_uring.c:2147 __io_sq_thread io_uring/sqpoll.c:193 [inline] io_sq_thread+0x708/0xf60 io_uring/sqpoll.c:252 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 6: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi d: e8 b4 ff ff ff callq 0xffffffc6 12: 31 c0 xor %eax,%eax 14: c3 retq 15: 90 nop 16: 65 8b 05 29 b8 87 7e mov %gs:0x7e87b829(%rip),%eax # 0x7e87b846 1d: 89 c1 mov %eax,%ecx 1f: 48 8b 34 24 mov (%rsp),%rsi 23: 81 e1 00 01 00 00 and $0x100,%ecx * 29: 65 48 8b 14 25 80 6f mov %gs:0x26f80,%rdx <-- trapping instruction 30: 02 00 32: a9 00 01 ff 00 test $0xff0100,%eax 37: 74 0e je 0x47 39: 85 c9 test %ecx,%ecx 3b: 74 35 je 0x72 3d: 8b .byte 0x8b 3e: 82 .byte 0x82