INFO: task syz-executor:4203 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21808 pid: 4203 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x83b/0xe50 mm/filemap.c:1356 lock_page include/linux/pagemap.h:625 [inline] truncate_inode_pages_range+0xa24/0xfe0 mm/truncate.c:394 evict+0x4dc/0x8d0 fs/inode.c:649 dispose_list fs/inode.c:680 [inline] evict_inodes+0x60c/0x6a0 fs/inode.c:734 generic_shutdown_super+0x93/0x300 fs/super.c:454 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f51eab61017 RSP: 002b:00007ffe1356ef78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f51eabf5120 RCX: 00007f51eab61017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe1356f030 RBP: 00007ffe1356f030 R08: 00007ffe13570030 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe135700c0 R13: 00007f51eabf5120 R14: 0000000000012c55 R15: 00007ffe13570100 Showing all locks held in the system: 1 lock held by ksoftirqd/0/14: 4 locks held by kworker/1:0/21: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000db7d00 (ser_release_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: ser_release+0x108/0x260 drivers/net/caif/caif_serial.c:308 #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #3: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by khungtaskd/27: #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:2/154: 1 lock held by dhcpcd/3854: #0: ffffffff8d43d3c8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xec/0xcf0 net/netlink/af_netlink.c:2226 2 locks held by getty/3950: #0: ffff88802c77d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4203: #0: ffff88814ca4c0e0 (&type->s_umount_key#65){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by kworker/1:12/4589: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000344fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by syz-executor/8348: #0: ffff888020578518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147976468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by syz.0.1767/9110: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d d0 bd 10 0c 48 89 de 5b e9 27 55 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 24 3b 89 7e 65 8b 15 25 3b 89 7e 81 e2 00 RSP: 0018:ffffc90000ddf898 EFLAGS: 00000246 RAX: ffffffff8452ac07 RBX: 0000000000000002 RCX: ffff888017a18000 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffffc90000ddf9f0 R08: ffffc90000ddfabf R09: ffffc90000ddfa80 R10: dffffc0000000000 R11: fffff520001bbf58 R12: 1ffff920001bbf40 R13: dffffc0000000000 R14: 0000000000000002 R15: 1ffff920001bbf1c FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5cc814c158 CR3: 000000005b6a0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: crng_make_state+0xb5/0x670 drivers/char/random.c:344 _get_random_bytes+0xfc/0x250 drivers/char/random.c:405 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:692 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x694/0xb40 drivers/net/netdevsim/dev.c:762 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287