INFO: task jbd2/sda1-8:3598 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:24384 pid:3598 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 jbd2_journal_wait_updates+0x18a/0x260 fs/jbd2/transaction.c:862 jbd2_journal_commit_transaction+0x8f9/0x60e0 fs/jbd2/commit.c:488 kjournald2+0x412/0x810 fs/jbd2/journal.c:210 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4027: #0: ffff88814cffb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/4252: #0: ffff88807de27958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807de27958 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5322 [inline] #0: ffff88807de27958 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5384 #1: ffff88807e392558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline] #1: ffff88807e392558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1995 [inline] #1: ffff88807e392558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x188/0x10c0 fs/ext4/inode.c:6250 2 locks held by syz.4.747/7228: 3 locks held by kworker/0:7/7414: 2 locks held by syz-executor/9067: #0: ffff88807e392460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff888025304030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #1: ffff888025304030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3884 2 locks held by syz-executor/9133: #0: ffff88807e392460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff88802530c030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #1: ffff88802530c030 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3884 3 locks held by syz.7.832/9145: 2 locks held by syz-executor/9154: #0: ffff88807e392460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff888025309810 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #1: ffff888025309810 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3884 2 locks held by dhcpcd/10726: #0: ffff888042e24a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff888042e24a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff888042e24a10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 #1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7228 Comm: syz.4.747 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:multiq3_encoder_reset drivers/comedi/drivers/multiq3.c:226 [inline] RIP: 0010:multiq3_attach+0x626/0x940 drivers/comedi/drivers/multiq3.c:316 Code: 00 74 08 48 89 df e8 d9 91 11 fa 8b 13 83 c2 0e b0 01 ee 41 80 3c 2c 00 74 08 48 89 df e8 c2 91 11 fa 8b 13 83 c2 0c 31 c0 ee <41> 80 3c 2c 00 74 08 48 89 df e8 ab 91 11 fa 8b 13 83 c2 0e b0 18 RSP: 0018:ffffc90013cc7ab8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88802ec3a9d0 RCX: 0000000000080000 RDX: 000000000000200c RSI: 000000000007ffff RDI: 0000000000080000 RBP: dffffc0000000000 R08: 0000000000000040 R09: fffffbfff2119058 R10: fffffbfff2119058 R11: 1ffffffff2119057 R12: 1ffff11005d8753a R13: 0000000007d25570 R14: 1ffff11004f23c92 R15: 0000000000fa4aaf FS: 00007ff54f0396c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0917578eb8 CR3: 0000000062ec6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: comedi_device_attach+0x514/0x700 drivers/comedi/drivers.c:1006 do_devconfig_ioctl drivers/comedi/comedi_fops.c:868 [inline] comedi_unlocked_ioctl+0x5a6/0x1050 drivers/comedi/comedi_fops.c:2173 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff54e18f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff54f039038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff54e3e6180 RCX: 00007ff54e18f749 RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000008 RBP: 00007ff54e213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff54e3e6218 R14: 00007ff54e3e6180 R15: 00007fffb1a0e3c8