From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7687B3033FB for ; Fri, 24 Jul 2026 13:18:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784899085; cv=none; b=qWfIx1/vOPsrP/SGjyW2iAp5bqty2VnG6q0kp6UiGmdw4nGDxZygyNmaMTMf5EjxhPw6Be2i25GVUAvVpzsgkNyZqJHeHk01RN/0cR61WLt99RA0Z9LoIxJ1V53E+2zS4LHYmyn2icw0Z6GyI8Yz3XAoqYNSyUNT20Sx3c97O8Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784899085; c=relaxed/simple; bh=cRexugdwP4TyrF+7e/sMoe9pCpfaQQVFbOeRPDFD7/E=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=ByTst5dGaWc+GOMf3eufBb4KARBuLZSOKilkreIEehteBUX5q1wYwFcRkfWi4sZkVVIjy8tbjwksMMRjrFnUQB7giY5oUaxlCyUIZYXfuxxzywh4dPqGIgesMO1oA/ZoVOuAwC1CBIr+bZzcti9r1v5Ettbm29gB4Dv0aAOyF44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.160.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa1-f69.google.com with SMTP id 586e51a60fabf-44ce386fe90so253801fac.2 for ; Fri, 24 Jul 2026 06:18:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784899082; x=1785503882; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=2B6CLpeZEZp9MNSgRwiiJ8iOKSUBo4+VrWy8DJIEj+U=; b=r7prKKn8+ZAeieLxYfHxPwIXVR7xM60M+sLko7cS9IV0YMquriZxb73f+V0wZJsVsd 2dV2PMlwe35gH5kYgUejxVniHwWqrAR9C9nXblA5NV0HXg6gxw8tH6sJqnY8jxxaOqYT wQAhjUbVCX1Wf0HCRGcP2e/VCCLBMH0IgXSZ+Kfo+BDH/oVg2rrClhvskMd1c5k2Wiux pxCNOxPQksZK5jUMZcCtOu4OHxwCOSXkoBBYwVpDqWUN1ubVOmBjwkfGX1jbwTOtwFTL gOG66le4UhzFo1x9dksAtTNDLOOICHJxTQGpjJofEVrZ726HUOJLzG9VdRtii6Warzpo iKzw== X-Forwarded-Encrypted: i=1; AHgh+Rqt9JvBJrmPy81GVzWzrOIskSFpDq1+ni4FGJC8S1VasJasfipRquvddzym2D6Ke2crqbdiZjI2S+UaxNY=@vger.kernel.org X-Gm-Message-State: AOJu0YzOu+ajte4sS+/hkFp+dfyCwvrzSyA7fyU1dMYtCn1weILcqVgw l3uV+lmqaTdpGjZwMGsailJfEWg2RjxhdyulqxiAvZeGdgrT5M+zx5SqxHgMVVIUW79x+BFGZcF CrGSp23UjvFhBsYrBfuYTe9xQ0c7y/B6wNgPWh6/Ok7T83l3qB/iG6JnaC3k= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:4fd2:b0:4a4:2424:eb14 with SMTP id 5614622812f47-4ab3542dd24mr5036122b6e.24.1784899082356; Fri, 24 Jul 2026 06:18:02 -0700 (PDT) Date: Fri, 24 Jul 2026 06:18:02 -0700 In-Reply-To: X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a63660a.dde6c935.cf6c8.0024.GAE@google.com> Subject: Re: [syzbot] [fuse?] INFO: task hung in fuse_chan_send From: syzbot To: jeffinphilip14@gmail.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: INFO: task hung in fuse_chan_send INFO: task syz.0.17:5898 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:24904 pid:5898 tgid:5898 ppid:5825 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 request_wait_answer fs/fuse/dev.c:743 [inline] __fuse_request_send fs/fuse/dev.c:757 [inline] fuse_chan_send+0x1065/0x1ac0 fs/fuse/dev.c:833 fuse_simple_request fs/fuse/fuse_i.h:1012 [inline] fuse_flush+0x66e/0x8b0 fs/fuse/file.c:504 filp_flush+0xbd/0x190 fs/open.c:1471 filp_close+0x1d/0x40 fs/open.c:1484 __range_close fs/file.c:793 [inline] __do_sys_close_range fs/file.c:854 [inline] __se_sys_close_range+0x3d3/0x900 fs/file.c:818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2b2b99ce59 RSP: 002b:00007ffdbb62c298 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ffdbb62c380 RCX: 00007f2b2b99ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 0000000000028b59 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2ff20000 R11: 0000000000000246 R12: 00007ffdbb62c3c0 R13: 00007f2b2bc15fac R14: 0000000000028bf9 R15: 00007f2b2bc15fa0 Showing all locks held in the system: 1 lock held by khungtaskd/26: #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u5:0/44: #0: ffff888042840140 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888042840140 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000467c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000467c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff888041e78ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331 4 locks held by kworker/u4:4/68: #0: ffff88803f2fd140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88803f2fd140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffff88801fc24440 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 #2: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #2: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 #3: ffff888044bed840 (&ifa->lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] #3: ffff888044bed840 (&ifa->lock){+...}-{3:3}, at: addrconf_dad_stop+0xb7/0x420 net/ipv6/addrconf.c:2144 2 locks held by getty/5091: #0: ffff88803f6020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900016002e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:7/5894: #0: ffff88801aca6940 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801aca6940 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90002fa7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90002fa7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88804d9da250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1fd/0x3b0 drivers/net/netdevsim/fib.c:1490 2 locks held by dhcpcd/6316: #0: ffff888041658800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff888041658800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline] #0: ffff888041658800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501 #1: ffffffff8e95ff28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e95ff28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 26 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Tested on: commit: 51cb1aa1 Merge tag 'loongarch-7.2' of git://git.kernel.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git console output: https://syzkaller.appspot.com/x/log.txt?x=13910105580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3c3d59be33cf7e9a dashboard link: https://syzkaller.appspot.com/bug?extid=a531d1b1fb0fa2a75a73 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Note: no patches were applied.