From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f78.google.com (mail-io1-f78.google.com [209.85.166.78]) (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 085131DA55 for ; Tue, 14 Oct 2025 11:22:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760440952; cv=none; b=L8f4fFoWNgueMj7Pb++njC/XDEmTTDOkf1UHBEUr56ONcMHvLgj25AfF200AitNSQj8fdsC/ZkFy5WYd6iTvLMDabkjzD23Pp6Stq0JmCXpFkOVwHgPtTCujZwaAkXBLNtOsgDGovQb/vokvs6iok7r1I8XVPG3Wb0AQCh2ow2Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760440952; c=relaxed/simple; bh=YjLkMwDFA6vXcTh6Q1R4+G+nJXR6z05oaavhnpJSEJU=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Bw4NmnU6Ipi5obNShzh4fTcfU+b8sgxT2vdSjhBmo79IDL4B3O8BElWQxxl5bF0izt3taOXP5pe4AbHe6VVtCo/CLRJnfa8GDMFbh/ks8NXmMQ2/CbHMBm2Xek+cAWcyB20MfIn3dZvgJ5wAOojMhdYWMO6IwhwkA9NpnEpWH0g= 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=209.85.166.78 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-io1-f78.google.com with SMTP id ca18e2360f4ac-930db3a16c9so1130059339f.0 for ; Tue, 14 Oct 2025 04:22:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760440949; x=1761045749; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ZlvmqkdNIV9+7iUIDE30YuWq23qFAdlP503srGLc0RQ=; b=MhOWC+JtHxcy0ok1i1bftSHkPP20b9N1JE4GzawgDG5Xwt3XrSZlNlFXRs/bsAabEp OisRn8oxyJzkmv3Ecbkn5j6780CBx92VK8wUG6SWxfFr6lbvXdqtnpDg2KkFf4az8rE8 JB+Rfn98hjp2Judx56z5K+wvkZJt9YG5ImgS+vfeyaFoi/X/MPFDitj1DCUj3lGqHPI9 0fyb2N7iALo0upA/fuTD1DhDsepRICpC6KO2HKFkt+SNqjEPE3BlslFQ+bpGztLuVICi KpZVZIauGnqrHuskViePV4yJ8ba0xDLKXJ4jCKkrVIb1/acS+PJWnOl+Oty5yNfwmbdx TvLg== X-Forwarded-Encrypted: i=1; AJvYcCWzwQKw3KGUhv5XJL+GWRlrKfD6ylS2QpKoG4dcp9hDq5x+VEAtH28wCiGM3WRakA06s/01RlsrurGWoXg=@vger.kernel.org X-Gm-Message-State: AOJu0YwWPEHdUt/vyICRdznN5Xo8Im1etLtUAn2s/xM/OsEJtH/cA4rt YhW9D9i0/GKNWt0P7SrULA5j21wp1lr1oOW4q9iONoCj/N/3OZC/Mjy4/ZMYxXZ2rbPGWYt6FCm OnxJYkuR1b6qYJTQQqQ/IJYatXbOUZ1g+xLQCQ4MwJgo4sKmdgQD1bID98Hk= X-Google-Smtp-Source: AGHT+IHBc+6nX6M44fQ1kDfbGruOPgZXzxBeLykvnAo5stWBgtzwS3shiyAOy+CriRvGJT3CZgCC9dZ4EODb0A6bvUDMR/ng2e3j Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:184c:b0:42f:9c5d:81b1 with SMTP id e9e14a558f8ab-42f9c5d821fmr180067085ab.32.1760440949025; Tue, 14 Oct 2025 04:22:29 -0700 (PDT) Date: Tue, 14 Oct 2025 04:22:29 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68ee3275.050a0220.91a22.0209.GAE@google.com> Subject: [syzbot] [mm?] INFO: task hung in migrate_pages_batch (4) From: syzbot To: akpm@linux-foundation.org, apopple@nvidia.com, byungchul@sk.com, david@redhat.com, gourry@gourry.net, joshua.hahnjy@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, matthew.brost@intel.com, rakie.kim@sk.com, syzkaller-bugs@googlegroups.com, ying.huang@linux.alibaba.com, ziy@nvidia.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 5472d60c129f Merge tag 'trace-v6.18-2' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=129bba7c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8dbddd36d9f68a5e dashboard link: https://syzkaller.appspot.com/bug?extid=f523acb98cd782b4872e compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3726636cb074/disk-5472d60c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c893bfa7d66d/vmlinux-5472d60c.xz kernel image: https://storage.googleapis.com/syzbot-assets/b93fdd7cec90/bzImage-5472d60c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f523acb98cd782b4872e@syzkaller.appspotmail.com INFO: task syz.4.865:9483 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.865 state:D stack:25592 pid:9483 tgid:9481 ppid:5824 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 io_schedule+0xbf/0x130 kernel/sched/core.c:7871 folio_wait_bit_common+0x3d5/0x9e0 mm/filemap.c:1330 folio_lock include/linux/pagemap.h:1141 [inline] migrate_folio_unmap mm/migrate.c:1241 [inline] migrate_pages_batch+0x1487/0x3bb0 mm/migrate.c:1882 migrate_pages_sync+0x4c5/0x8a0 mm/migrate.c:2026 migrate_pages+0x1b5f/0x23a0 mm/migrate.c:2108 compact_zone+0x2018/0x4750 mm/compaction.c:2647 compact_node+0x1a3/0x2c0 mm/compaction.c:2916 compact_nodes mm/compaction.c:2938 [inline] sysctl_compaction_handler mm/compaction.c:2989 [inline] sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2976 proc_sys_call_handler+0x442/0x570 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0xa24/0x12e0 fs/splice.c:738 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x18f/0x6c0 fs/splice.c:1161 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1230 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1425 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f298278eec9 RSP: 002b:00007f2983563038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f29829e6090 RCX: 00007f298278eec9 RDX: 00002000000000c0 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007f2982811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f29829e6128 R14: 00007f29829e6090 R15: 00007ffdc1780a28 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900000f7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff88807d510240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b6/0x6da0 drivers/net/netdevsim/fib.c:1490 1 lock held by khungtaskd/31: #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 6 locks held by kworker/1:2/3733: #0: ffff888144ec0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000d22fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff8881447a3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff8881447a3198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff88801b7bb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88801b7bb198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #4: ffff888053dad160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888053dad160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 #5: ffff888075830068 (&state->mutex){+.+.}-{4:4}, at: az6007_write drivers/media/usb/dvb-usb-v2/az6007.c:178 [inline] #5: ffff888075830068 (&state->mutex){+.+.}-{4:4}, at: az6007_power_ctrl+0x2f0/0x800 drivers/media/usb/dvb-usb-v2/az6007.c:703 1 lock held by acpid/5169: #0: ffffffff8e3cfa38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by getty/5577: #0: ffff88814d0060a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5797: 4 locks held by udevd/5809: #0: ffff8880496228b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff888034640088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88804ae63008 (kn->active#24){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88804ae63008 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88801b7bb198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline] #3: ffff88801b7bb198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz-executor/5814: #0: ffffffff8e3cfa38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 4 locks held by kworker/0:4/5869: #0: ffff888144ec0d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900043a7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff888029493198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888029493198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888031acf198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff888031acf198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006 1 lock held by udevd/8053: #0: ffff888142f51358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.4.865/9483: #0: ffff88803451c420 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105 1 lock held by syz.3.1367/11417: #0: ffffffff8e3cf900 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x672/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: d7 75 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 e6 24 00 fb f4 0c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c2 RAX: 000000000252e2c3 RBX: 0000000000000000 RCX: ffffffff8b6532d9 RDX: 0000000000000000 RSI: ffffffff8db02c74 RDI: ffffffff8bf1d240 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908329d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fc0eff8 CR3: 000000007dd80000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f3/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup