INFO: task syz.0.16:6464 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:26120 pid:6464 tgid:6462 ppid:6351 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 rwsem_down_write_slowpath+0x899/0x1040 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1bc/0x200 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:536 [inline] exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 __mmput+0x118/0x430 kernel/fork.c:1175 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 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+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91cc3988f9 RSP: 002b:00007f91cd27e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f91cc5c6088 RCX: 00007f91cc3988f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f91cc5c6088 RBP: 00007f91cc5c6080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f91cc5c608c R13: 0000000000000000 R14: 00007ffcd6a9a8b0 R15: 00007ffcd6a9a998 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5182: 2 locks held by getty/5584: #0: ffff8880372da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u9:2/5835: #0: ffff88806d2a1948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88806d2a1948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90003d47c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90003d47c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888072a04ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 1 lock held by syz.0.16/6464: #0: ffff8880367e8f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff8880367e8f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.1.17/6487: #0: ffff88803247a800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88803247a800 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz-executor/6489: #0: ffff88803247c080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88803247c080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.2.18/6508: #0: ffff88807f8e7180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88807f8e7180 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.3.20/6538: #0: ffff888028b41bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff888028b41bc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.4.22/6573: #0: ffff888022acb440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff888022acb440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz-executor/6577: #0: ffff88807ef24cc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88807ef24cc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.5.23/6603: #0: ffff888022acccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff888022acccc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.6.24/6635: #0: ffff88813fe31bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88813fe31bc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.7.25/6670: #0: ffff88807e897180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff88807e897180 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.8.26/6700: #0: ffff888032479bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff888032479bc0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 1 lock held by syz.9.28/6731: #0: ffff8880367ec080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline] #0: ffff8880367ec080 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0xa10 mm/mmap.c:1310 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235 Code: 80 16 00 00 83 fa 02 75 21 48 8b 91 88 16 00 00 48 8b 32 48 8d 7e 01 8b 89 84 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 cc cc cc cc cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc90000a08ea0 EFLAGS: 00000006 RAX: ffffffff816b122b RBX: ffff8880b87243c8 RCX: ffff88801dac0000 RDX: 0000000000010000 RSI: ffffffff8c27d0e0 RDI: 0000000000000001 RBP: ffffc90000a08f98 R08: ffffffff9011cfb7 R09: 1ffffffff20239f6 R10: dffffc0000000000 R11: fffffbfff20239f7 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90000a08f20 R15: 1ffff920001411e0 FS: 0000000000000000(0000) GS:ffff888125557000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558ed4d4e8 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: sched_clock+0xb/0x60 arch/x86/kernel/tsc.c:294 sched_clock_cpu+0x74/0x440 kernel/sched/clock.c:400 irqtime_account_irq+0x65/0x1b0 kernel/sched/cputime.c:68 account_hardirq_exit include/linux/vtime.h:154 [inline] __irq_exit_rcu+0x22/0x150 kernel/softirq.c:720 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: ce 6b 02 c3 cc cc cc cc cc cc cc 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 e3 f2 19 00 fb f4 fc e9 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: 000000000015a971 RBX: ffffffff819a91fa RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8defad8d RDI: ffffffff8c27d100 RBP: ffffc90000197f10 R08: ffff8880b873399b R09: 1ffff110170e6733 R10: dffffc0000000000 R11: ffffed10170e6734 R12: 0000000000000001 R13: 1ffff11003b58000 R14: 0000000000000001 R15: 1ffff11003b58000 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147