INFO: task syz.3.510:8010 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.510 state:D stack:25816 pid:8010 tgid:8010 ppid:5807 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 bdev_release+0x15a/0x6d0 block/bdev.c:1144 blkdev_release+0x15/0x20 block/fops.c:706 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f39fbd9bf79 RSP: 002b:00007ffe6d9974e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f39fc017da0 RCX: 00007f39fbd9bf79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f39fc017da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f39fc017cb0 R11: 0000000000000246 R12: 0000000000034ac8 R13: 00007f39fc01609c R14: 0000000000034a96 R15: 00007f39fc016090 INFO: task syz.3.510:8013 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.510 state:D stack:27240 pid:8013 tgid:8010 ppid:5807 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1023/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 bdev_release+0x15a/0x6d0 block/bdev.c:1144 blkdev_release+0x15/0x20 block/fops.c:706 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f39fbd9bf79 RSP: 002b:00007f39fcc00028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f39fc015fa0 RCX: 00007f39fbd9bf79 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000005 RBP: 00007f39fbe327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f39fc016038 R14: 00007f39fc015fa0 R15: 00007ffe6d997388 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7f2e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by khungtaskd/31: #0: ffffffff8e7e7220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:9/3663: #0: ffff88801cab9148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3250 #1: ffffc9000d2dfd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3251 #2: ffffffff905e6370 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670 #3: ffffffff8e7f2d00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 2 locks held by getty/5565: #0: ffff8880348cb0a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 1 lock held by udevd/5800: #0: ffff888027335358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 2 locks held by syz-executor/5808: 1 lock held by udevd/6019: #0: ffff888027463358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 1 lock held by syz.3.510/8010: #0: ffff888027463358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1144 1 lock held by syz.3.510/8013: #0: ffff888027463358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1144 5 locks held by syz.5.969/9929: 2 locks held by syz.5.969/9930: 3 locks held by syz.5.969/9931: 2 locks held by syz.5.969/9936: 2 locks held by syz.5.969/9937: 3 locks held by syz.5.969/9938: 3 locks held by syz.5.969/9939: 1 lock held by syz.5.992/10053: #0: ffffffff8e7f2d00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 ============================================= 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 01/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xcc3/0xfe0 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__asan_memcpy+0x2c/0x60 mm/kasan/shadow.c:106 Code: 1e fa 41 54 49 89 fc 55 48 89 f5 53 48 89 d3 48 8b 4c 24 18 31 d2 48 89 de 48 89 ef e8 cd f1 ff ff 84 c0 74 2b 48 8b 4c 24 18 01 00 00 00 48 89 de 4c 89 e7 e8 b4 f1 ff ff 84 c0 74 12 48 89 RSP: 0018:ffffc900001178f8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000020 RCX: ffffffff8571b805 RDX: 0000000000000001 RSI: 0000000000000020 RDI: ffffc90000117948 RBP: ffffc90000117948 R08: 0000000000000000 R09: fffff52000022f2c R10: ffffc90000117967 R11: 000000004e4334a1 R12: ffff8880b8436e60 R13: ffff8880b8436e60 R14: ffffc90000117a78 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881243a8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe71a7e6ad8 CR3: 000000007968c000 CR4: 00000000003526f0 Call Trace: crng_fast_key_erasure+0x1b5/0x260 drivers/char/random.c:328 crng_make_state+0x1c2/0x6c0 drivers/char/random.c:392 _get_random_bytes+0x11c/0x220 drivers/char/random.c:406 eth_random_addr include/linux/etherdevice.h:238 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:825 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline] nsim_dev_trap_report_work+0x370/0xd10 drivers/net/netdevsim/dev.c:921 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245