INFO: task syz.1.294:5215 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.294 state:D stack:22080 pid:5215 ppid:4279 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 perf_pending_task_sync kernel/events/core.c:5041 [inline] _free_event+0x176/0x1050 kernel/events/core.c:5047 put_event kernel/events/core.c:5172 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5297 perf_release+0x37/0x40 kernel/events/core.c:5307 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 get_signal+0x118d/0x1340 kernel/signal.c:2661 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:295 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:306 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f24a499e159 RSP: 002b:00007f24a5950fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f24a4c25fa0 RCX: 00007f24a499e159 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f24a4a3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f24a4c26038 R14: 00007f24a4c25fa0 R15: 00007ffec6a12fa8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e170 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2e990 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6529 2 locks held by getty/4033: #0: ffff8880308f9098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198 2 locks held by syz.2.1057/7567: 2 locks held by syz.3.1060/7579: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0xf0e/0xf50 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: 7579 Comm: syz.3.1060 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline] RIP: 0010:rcu_is_watching+0x4/0xa0 kernel/rcu/tree.c:720 Code: a2 5e c6 08 48 c7 c7 e0 42 b3 8c 4c 89 f6 e8 d3 d8 d1 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 57 41 56 <53> 65 ff 05 6c 45 96 7e e8 1f 73 c6 08 89 c3 83 f8 08 73 60 49 bf RSP: 0018:ffffc90005c46dc8 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8163fad4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e20b468 RBP: ffffc90005c46ee8 R08: ffffffff8e20b46f R09: 1ffffffff1c4168d R10: dffffc0000000000 R11: fffffbfff1c4168e R12: 0000000000000000 R13: 1ffff92000b88dc8 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f91d8cd96c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5caafef2f8 CR3: 000000002ff3c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe3/0x4a0 kernel/locking/lockdep.c:5649 seqcount_lockdep_reader_access+0x10f/0x1d0 include/linux/seqlock.h:102 ktime_get_coarse_real_ts64+0x2b/0x120 kernel/time/timekeeping.c:2267 current_time+0x8e/0x2c0 fs/inode.c:2538 file_update_time+0x9c/0x370 fs/inode.c:2172 __generic_file_write_iter+0xdf/0x2a0 mm/filemap.c:3940 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 __kernel_write_iter+0x298/0x690 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x40a/0x840 fs/coredump.c:977 elf_core_dump+0x30ca/0x3630 fs/binfmt_elf.c:2354 do_coredump+0x16c1/0x2480 fs/coredump.c:824 get_signal+0x1093/0x1340 kernel/signal.c:2870 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:319 exc_general_protection+0x164/0x1f0 arch/x86/kernel/traps.c:729 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:602 RIP: 0033:0x7f91d7d9e161 Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:0000200000000040 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f91d8026090 RCX: 00007f91d7d9e159 RDX: 00002000000000c0 RSI: 0000200000000040 RDI: 000000000a000600 RBP: 00007f91d7e3506b R08: 00002000000001c0 R09: 00002000000001c0 R10: 0000200000000100 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f91d8026128 R14: 00007f91d8026090 R15: 00007fffabc71c18