INFO: task syz.3.37:6496 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.3.37 state:D stack:26904 pid:6496 tgid:6496 ppid:6253 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1742/0x4c30 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x926/0x10e0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28b/0xb30 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1129 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x22f0 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f65f3f8eec9 RSP: 002b:00007ffcfc6bc0b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f65f3f8eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffcfc6bc11c R08: 00000005fc6bc1af R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003 R13: 00000000000927c0 R14: 000000000001f666 R15: 00007ffcfc6bc170 INFO: task syz.3.37:6496 is blocked on an rw-semaphore, but the owner is not found. INFO: task syz.4.21:6517 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.4.21 state:D stack:25768 pid:6517 tgid:6516 ppid:6254 task_flags:0x40054c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1742/0x4c30 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x926/0x10e0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28b/0xb30 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1129 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x22f0 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1252/0x1300 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x217/0x300 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f486378eec9 RSP: 002b:00007f486455a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f48639e5fa8 RCX: 00007f486378eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f48639e5fa8 RBP: 00007f48639e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48639e6038 R14: 00007fff9ab003e0 R15: 00007fff9ab004c8 INFO: task syz.4.21:6517 is blocked on an rw-semaphore, but the owner is not found. Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8db372a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8db372a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8db372a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by klogd/5082: 2 locks held by udevd/5093: #0: ffffffff8dbeb330 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1484 [inline] #0: ffffffff8dbeb330 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1537 #1: ffff888042d981e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #1: ffff888042d981e0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x12d/0x1c50 mm/mmap.c:1727 2 locks held by getty/5479: #0: ffff88802ee830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5ce/0x1ab0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/6131: #0: ffff88802573d7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff88802573d7e0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578 1 lock held by udevd/6223: #0: ffff888026452220 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff888026452220 (&mm->mmap_lock){++++}-{4:4}, at: __vm_munmap+0x15c/0x3d0 mm/vma.c:3152 1 lock held by syz-executor/6241: #0: ffff8880264557e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880264557e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz-executor/6244: #0: ffff8880491ad7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880491ad7e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz-executor/6247: #0: ffff88807c754d20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807c754d20 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz-executor/6253: #0: ffff88807c7557e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807c7557e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz-executor/6254: #0: ffff888042d9a220 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff888042d9a220 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz.3.37/6496: #0: ffff8880491ab7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880491ab7a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz.4.21/6517: #0: ffff88801eb1ed60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88801eb1ed60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by sed/6520: #0: ffff888042c09760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff888042c09760 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578 1 lock held by syz-executor/6523: #0: ffff8880323ba220 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880323ba220 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 2 locks held by syz-executor/6531: #0: ffffffff8dbeb330 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1484 [inline] #0: ffffffff8dbeb330 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1537 #1: ffff888042c0d7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #1: ffff888042c0d7e0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x12d/0x1c50 mm/mmap.c:1727 1 lock held by syz.9.73/6711: #0: ffff8880491a81e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880491a81e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz.5.75/6716: #0: ffff88803213c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88803213c260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz.6.76/6718: #0: ffff8880491aace0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880491aace0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 1 lock held by syz.8.77/6719: #0: ffff88803213ace0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88803213ace0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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/0x2e0 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+0x15af/0x15f0 kernel/hung_task.c:491 kthread+0x711/0x890 kernel/kthread.c:463 ret_from_fork+0x435/0x7c0 arch/x86/kernel/process.c:148 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: 779 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x1/0x110 lib/smp_processor_id.c:13 Code: 20 ac 7d 8b 48 c7 c6 60 ac 7d 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 05 be 60 0f 07 48 89 44 24 08 RSP: 0018:ffffc90003567710 EFLAGS: 00000087 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b7dac60 RDI: ffffffff8b7dac20 RBP: ffffffff84827fc7 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff520006acef8 R12: 0000000000000000 R13: ffffffff994b4e88 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881266f3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c007bcf010 CR3: 00000000496c8000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0x87/0x540 lib/debugobjects.c:818 debug_timer_activate kernel/time/timer.c:793 [inline] __mod_timer+0xa4f/0xf30 kernel/time/timer.c:1124 queue_delayed_work_on+0x182/0x270 kernel/workqueue.c:2559 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa55/0x16a0 kernel/workqueue.c:3319 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3400 kthread+0x711/0x890 kernel/kthread.c:463 ret_from_fork+0x435/0x7c0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245