INFO: task syz.0.1243:10581 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1243 state:D stack:26176 pid:10581 ppid: 8693 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff12fd38ec9 RSP: 002b:00007ff12dfa0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffea RBX: 00007ff12ff8ffa0 RCX: 00007ff12fd38ec9 RDX: 0000200000000840 RSI: 000000004008240b RDI: 0000000000000005 RBP: 00007ff12fdbbf91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff12ff90038 R14: 00007ff12ff8ffa0 R15: 00007ffc57e16dc8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3951: #0: ffff88802c9ca098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 3 locks held by kworker/u4:18/10300: 2 locks held by kworker/1:1/11788: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002e5fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 2 locks held by syz.4.2192/14010: #0: ffffffff8c169d68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by syz.3.2189/14012: #0: ffffffff8c169d68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.6.2227/14133: #0: ffffffff8c169d68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 ============================================= 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 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14000 Comm: syz.6.2184 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:kasan_check_range+0x1ab/0x290 mm/kasan/generic.c:-1 Code: 4d 89 d6 4d 8d 56 07 4d 85 f6 4d 0f 49 d6 49 83 e2 f8 4d 29 d6 74 12 41 80 39 00 0f 85 a0 00 00 00 49 ff c1 49 ff ce 75 ee 5b <41> 5e 41 5f c3 84 db 75 61 f7 c3 00 ff 00 00 75 5e f7 c3 00 00 ff RSP: 0018:ffffc9000305ef68 EFLAGS: 00000056 RAX: 0000000000000001 RBX: 00000000000002bf RCX: ffffffff815c0b14 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbd110 RBP: ffffc9000305f1d0 R08: dffffc0000000000 R09: fffffbfff1ff7a23 R10: fffffbfff1ff7a23 R11: 1ffffffff1ff7a22 R12: ffff8880798f6450 R13: ffff8880798f5940 R14: 0000000000000001 R15: dffffc0000000001 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f439b32b198 CR3: 0000000072856000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] __lock_acquire+0xdb4/0x7c60 kernel/locking/lockdep.c:4982 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:388 [inline] delete_from_page_cache+0x117/0x190 mm/filemap.c:265 truncate_inode_page+0x8d/0xb0 mm/truncate.c:219 shmem_undo_range+0x4dc/0x1880 mm/shmem.c:960 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x20d/0xa00 mm/shmem.c:1145 evict+0x485/0x870 fs/inode.c:647 __dentry_kill+0x431/0x650 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x5ee/0x930 fs/file_table.c:319 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x11ef Code: Unable to access opcode bytes at RIP 0x11c5. RSP: 002b:00002000000000e8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ff721965180 RCX: 00007ff72170dec9 RDX: 0000200000000180 RSI: 00002000000000e0 RDI: 00000000000c0000 RBP: 00007ff721790f91 R08: 0000200000000280 R09: 0000200000000280 R10: 00002000000001c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff721965218 R14: 00007ff721965180 R15: 00007ffd5b096698