INFO: task syz.0.9706:32487 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.9706 state:D stack:26672 pid:32487 ppid:29774 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x982/0x2480 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xc4/0x1350 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 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc788b9cdd9 RSP: 002b:00007fc789a25028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: 0000000000000045 RBX: 00007fc788e16090 RCX: 00007fc788b9cdd9 RDX: 0000000000000050 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007fc788c32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc788e16128 R14: 00007fc788e16090 R15: 00007ffdc09d5ec8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2df70 (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: ffffffff8cb2e790 (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: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4031: #0: ffff88803010f098 (&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+0x429/0x1390 drivers/tty/n_tty.c:2198 3 locks held by syz.5.10993/3928: 2 locks held by syz.5.10993/3952: 1 lock held by syz.1.11040/4033: 2 locks held by syz.2.11055/4109: ============================================= 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 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 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: 4109 Comm: syz.2.11055 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:unwind_next_frame+0x97c/0x20b0 arch/x86/kernel/unwind_orc.c:-1 Code: 84 c0 0f 85 72 11 00 00 4d 89 f7 49 c1 ef 03 43 0f b6 04 2f 84 c0 0f 85 7d 11 00 00 0f b6 45 01 83 e0 03 ff 24 c5 10 80 89 8a <4c> 89 74 24 70 4c 89 64 24 20 4c 8d 73 08 4d 89 f4 49 c1 ec 03 43 RSP: 0018:ffffc9000557e570 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000557e648 RCX: ffffffff8e3517dc RDX: ffffc9000557f240 RSI: ffffffff8e3517d8 RDI: ffffffff81391adf RBP: ffffffff8ea78a6c R08: 0000000000000001 R09: 0000000000000009 R10: dffffc0000000000 R11: fffff52000aafcd5 R12: ffffffff8ea78a68 R13: dffffc0000000000 R14: ffffffff8ea78a6d R15: 1ffffffff1d4f14d FS: 00007fbc447126c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc439ea2f8 CR3: 000000005b345000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 save_stack+0x121/0x230 mm/page_owner.c:127 __set_page_owner+0x19/0x60 mm/page_owner.c:190 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657 __folio_alloc+0xe/0x30 mm/page_alloc.c:5689 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243 shmem_alloc_folio mm/shmem.c:1589 [inline] shmem_alloc_and_acct_folio+0x463/0xbc0 mm/shmem.c:1613 shmem_get_folio_gfp+0x1361/0x3400 mm/shmem.c:1941 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 __kernel_write_iter+0x285/0x650 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x412/0x850 fs/coredump.c:977 elf_core_dump+0x30a6/0x35d0 fs/binfmt_elf.c:2354 do_coredump+0x165b/0x22f0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xc4/0x1350 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:1485 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 002b:0000200000000048 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fbc43a15fa0 RCX: 00007fbc4379cdd9 RDX: 0000200000000080 RSI: 0000200000000040 RDI: 0000000000008000 RBP: 00007fbc43832d69 R08: 0000200000000500 R09: 0000200000000500 R10: 00002000000000c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fbc43a16038 R14: 00007fbc43a15fa0 R15: 00007ffc8dddffe8