INFO: task syz.4.1111:10216 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1111 state:D stack:23016 pid:10216 ppid:6681 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5244 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5250 put_event kernel/events/core.c:5378 [inline] perf_event_release_kernel+0x842/0x8d0 kernel/events/core.c:5503 perf_release+0x3b/0x40 kernel/events/core.c:5513 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb2f6b9cdd9 RSP: 002b:00007fb2f79c3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: fffffffffffffffc RBX: 00007fb2f6e15fa0 RCX: 00007fb2f6b9cdd9 RDX: 0000000000000048 RSI: 0000200000000600 RDI: 000000000000000a RBP: 00007fb2f6c32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb2f6e16038 R14: 00007fb2f6e15fa0 R15: 00007fff1c8f0568 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5530: #0: ffff88802d8db0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 1 lock held by syz.3.1786/13231: 2 locks held by syz.3.1794/13251: 1 lock held by syz.3.1818/13326: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 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+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13251 Comm: syz.3.1794 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:815 [inline] RIP: 0010:page_ext_put+0x2a/0xb0 mm/page_ext.c:533 Code: 66 0f 1f 00 53 48 89 fb e8 d3 e5 9c ff 48 85 db 0f 84 93 00 00 00 e8 a5 14 9c 08 89 c3 31 ff 89 c6 e8 6a e9 9c ff 85 db 74 10 91 a8 86 ff 84 c0 74 0e e8 a8 e5 9c ff eb 56 e8 a1 e5 9c ff eb RSP: 0018:ffffc9001024f410 EFLAGS: 00000202 RAX: ffffffff81ea3c46 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff888017df0000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001024f610 R08: ffff88801b54dc17 R09: 1ffff110036a9b82 R10: dffffc0000000000 R11: ffffed10036a9b83 R12: dffffc0000000000 R13: 000000110c464000 R14: ffffea0001b28a80 R15: ffff888064fad320 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd4a79aff0 CR3: 00000000480cd000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] zap_pte_range mm/memory.c:1429 [inline] zap_pmd_range mm/memory.c:1571 [inline] zap_pud_range mm/memory.c:1600 [inline] zap_p4d_range mm/memory.c:1621 [inline] unmap_page_range+0x1ad9/0x3000 mm/memory.c:1642 unmap_vmas+0x286/0x3f0 mm/memory.c:1732 exit_mmap+0x238/0xb90 mm/mmap.c:3302 __mmput+0x118/0x3c0 kernel/fork.c:1356 exit_mm+0x1f2/0x2c0 kernel/exit.c:569 do_exit+0x8dd/0x2460 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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+0x9/0x30 kernel/entry/common.c:315 exc_general_protection+0x168/0x1f0 arch/x86/kernel/traps.c:745 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602 RIP: 0033:0x7f657199cde1 Code: Unable to access opcode bytes at 0x7f657199cdb7. RSP: 002b:00002000000001d0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f6571c15fa0 RCX: 00007f657199cdd9 RDX: 0000000000000000 RSI: 00002000000001d0 RDI: 0000000000000000 RBP: 00007f6571a32d69 R08: 0000200000000a40 R09: 0000200000000a40 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6571c16038 R14: 00007f6571c15fa0 R15: 00007ffd4a79bf08