INFO: task syz.4.685:8487 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.685 state:D stack:25096 pid:8487 tgid:8487 ppid:7685 task_flags:0x40044c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088 __down_read_common kernel/locking/rwsem.c:1263 [inline] __down_read kernel/locking/rwsem.c:1276 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541 mmap_read_lock include/linux/mmap_lock.h:412 [inline] exit_mm+0xcc/0x2c0 kernel/exit.c:557 do_exit+0x648/0x2300 kernel/exit.c:947 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline] irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73 exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f35f2156718 RSP: 002b:00007fffbb50ac88 EFLAGS: 00010202 RAX: 0000200000000080 RBX: 0000000000000004 RCX: 006c6c756e2f7665 RDX: 000000000000000a RSI: 6c756e2f7665642f RDI: 0000200000000080 RBP: 00007f35f23b7ba0 R08: 00007f35f2000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007f35f23b608c R13: 00007fffbb50ad80 R14: fffffffffffffffe R15: 00007fffbb50ada0 INFO: task syz.4.685:8488 blocked for more than 144 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.685 state:D stack:23512 pid:8488 tgid:8487 ppid:7685 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088 __down_read_common kernel/locking/rwsem.c:1263 [inline] __down_read kernel/locking/rwsem.c:1276 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541 mmap_read_lock include/linux/mmap_lock.h:412 [inline] __mm_populate+0x16f/0x380 mm/gup.c:1962 do_mlock+0x625/0x740 mm/mlock.c:653 __do_sys_mlock mm/mlock.c:661 [inline] __se_sys_mlock mm/mlock.c:659 [inline] __x64_sys_mlock+0x60/0x70 mm/mlock.c:659 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f35f218e9a9 RSP: 002b:00007f35f3092038 EFLAGS: 00000246 ORIG_RAX: 0000000000000095 RAX: ffffffffffffffda RBX: 00007f35f23b5fa0 RCX: 00007f35f218e9a9 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000000000 RBP: 00007f35f2210d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f35f23b5fa0 R15: 00007fffbb50ab28 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:4/59: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644 #1: ffff8880b8724008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937 2 locks held by getty/5612: #0: ffff88814db260a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by kworker/1:5/5899: 3 locks held by kworker/0:6/7828: #0: ffff888144af9548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888144af9548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900049a7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900049a7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff888145755198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff888145755198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 1 lock held by syz.4.685/8487: #0: ffff888053892ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff888053892ce0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.4.685/8488: #0: ffff888053892ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff888053892ce0 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x16f/0x380 mm/gup.c:1962 1 lock held by syz.4.685/8491: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 7489 Comm: kworker/u8:18 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x5a/0x360 kernel/locking/lockdep.c:5834 Code: 0c 9d 49 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 0f 9d 49 11 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 f8 1b 46 0e 73 16 c1 03 09 00 84 c0 75 0d f6 05 f8 fe 2f 0e 01 0f 84 d7 01 00 00 RSP: 0018:ffffc90003fc7980 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e53d8a0 RBP: ffffffff8b4d0e32 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8b4d0d60 R12: 0000000000000002 R13: ffffffff8e53d8a0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0dd6dd1ff0 CR3: 00000000780e6000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245