INFO: task syz.7.2741:14052 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2741 state:D stack:20960 pid:14052 ppid:10682 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189 mmap_write_lock include/linux/mmap_lock.h:71 [inline] exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 __mmput+0x118/0x3c0 kernel/fork.c:1200 exit_mm+0x1e6/0x2c0 kernel/exit.c:565 do_exit+0x8c1/0x2400 kernel/exit.c:867 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0xe00000004 RSP: 002b:0000200000000208 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fe5101e6090 RCX: 00007fe50ff8f749 RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000000088100000 RBP: 00007fe510013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fe5101e6128 R14: 00007fe5101e6090 R15: 00007ffe77663f38 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by udevd/3636: #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline] #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline] #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590 #1: ffff88807ceadb58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807ceadb58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline] #1: ffff88807ceadb58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline] #1: ffff88807ceadb58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590 2 locks held by getty/4025: #0: ffff888030423098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4253: #0: ffff88802b5bcc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88802b5bcc58 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518 2 locks held by kworker/u4:6/4351: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004adfd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:7/4369: 1 lock held by syz-executor/10690: #0: ffff8880274117d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff8880274117d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 2 locks held by syz-executor/10694: #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline] #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline] #0: ffffffff8c9c5490 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590 #1: ffff88807774f958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807774f958 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline] #1: ffff88807774f958 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline] #1: ffff88807774f958 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590 1 lock held by udevd/13705: #0: ffff88807e3e9f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807e3e9f58 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x141/0x290 mm/mmap.c:2933 1 lock held by udevd/14038: #0: ffff8880777488d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff8880777488d8 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x141/0x290 mm/mmap.c:2933 1 lock held by syz.7.2741/14052: #0: ffff888026e68158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff888026e68158 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 1 lock held by syz.9.2745/14059: #0: ffff88807b9b4c58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff88807b9b4c58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 1 lock held by syz.7.2747/14061: #0: ffff888026e6a6d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff888026e6a6d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 1 lock held by modprobe/14062: #0: ffff88807b9b35d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807b9b35d8 (&mm->mmap_lock){++++}-{3:3}, at: setup_arg_pages+0x301/0xab0 fs/exec.c:802 1 lock held by syz.8.2748/14063: #0: ffff88807b9b26d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline] #0: ffff88807b9b26d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 82 Comm: kswapd0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:task_irq_context kernel/locking/lockdep.c:4558 [inline] RIP: 0010:__lock_acquire+0x474/0x7c50 kernel/locking/lockdep.c:4987 Code: 8b 84 24 88 00 00 00 4c 8d b0 c4 0a 00 00 4c 89 f0 48 c1 e8 03 48 89 84 24 d0 00 00 00 42 0f b6 04 00 84 c0 0f 85 63 62 00 00 <31> c0 4c 89 b4 24 b8 00 00 00 41 83 3e 00 0f 95 c0 09 c3 c1 e3 0d RSP: 0018:ffffc90001596f20 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff110030f98df RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880187cc6e8 RBP: ffffc90001597170 R08: dffffc0000000000 R09: 0000000000000001 R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: ffff8880187cc6d8 R13: 0000000000000000 R14: ffff8880187cc644 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f7705f38e CR3: 000000000c68e000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0x6a/0x490 lib/debugobjects.c:698 debug_rcu_head_queue kernel/rcu/rcu.h:190 [inline] call_rcu+0xa7/0x980 kernel/rcu/tree.c:2834 __dentry_kill+0x4ef/0x650 fs/dcache.c:625 shrink_dentry_list+0x39b/0x6a0 fs/dcache.c:1206 prune_dcache_sb+0x10b/0x170 fs/dcache.c:1287 super_cache_scan+0x30f/0x440 fs/super.c:104 do_shrink_slab+0x504/0xdb0 mm/vmscan.c:853 shrink_slab+0x1b1/0x720 mm/vmscan.c:1013 shrink_node_memcgs mm/vmscan.c:6147 [inline] shrink_node+0x6e4/0x28d0 mm/vmscan.c:6176 kswapd_shrink_node mm/vmscan.c:6968 [inline] balance_pgdat mm/vmscan.c:7158 [inline] kswapd+0x1bc4/0x32c0 mm/vmscan.c:7418 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295