INFO: task syz.6.8047:27654 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.8047 state:D stack:23808 pid:27654 ppid: 19702 flags:0x00004006 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 get_signal+0x1222/0x12c0 kernel/signal.c:2672 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: 0033:0x7fec13472fc9 RSP: 002b:00007fec116d9fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007fec136c9fa0 RCX: 00007fec13472fc9 RDX: 0000200000000140 RSI: 0000200000000380 RDI: 000000000c200000 RBP: 00007fec134f5f91 R08: 0000200000000b80 R09: 0000200000000b80 R10: 0000200000000b40 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fec136ca038 R14: 00007fec136c9fa0 R15: 00007ffe984e47c8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3952: #0: ffff88814d077098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by kworker/0:15/7117: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000360fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/1:19/9262: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002ecfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 2 locks held by syz.2.9177/30990: 2 locks held by syz.7.9203/31060: #0: ffffffff8c169e68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c1211e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 2 locks held by syz.0.9207/31074: #0: ffffffff96115918 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313 #1: ffffffff8c169e68 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 ============================================= 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: 4173 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:___might_sleep+0x180/0x600 kernel/sched/core.c:9626 Code: 03 00 00 45 03 7d 00 44 3b 7c 24 2c 75 61 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 f6 84 24 a1 00 00 00 02 <74> 43 4c 8d 7a 2c 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 RSP: 0018:ffffc90002e8f860 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff920005d1f14 RCX: 0d926b93bcedbc00 RDX: ffff888027ef3b80 RSI: ffffffff8a0b2f00 RDI: ffffffff8a59e580 RBP: ffffc90002e8f978 R08: dffffc0000000000 R09: fffffbfff1ff7c32 R10: fffffbfff1ff7c32 R11: 1ffffffff1ff7c31 R12: dffffc0000000000 R13: ffff888027ef3fbc R14: 1ffff11004fde7f7 R15: 0000000000000000 FS: 000055556bc67500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f070e572ad8 CR3: 00000000730d9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_sock_nested+0x5b/0x100 net/core/sock.c:3258 lock_sock include/net/sock.h:1731 [inline] tcp_recvmsg+0x32e/0x710 net/ipv4/tcp.c:2562 inet_recvmsg+0x136/0x1e0 net/ipv4/af_inet.c:868 sock_recvmsg_nosec net/socket.c:968 [inline] sock_recvmsg net/socket.c:986 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1067 call_read_iter include/linux/fs.h:2167 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd18eb9799d Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d c1 ab 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec RSP: 002b:00007ffc51946808 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd18eb9799d RDX: 0000000000000004 RSI: 00007ffc5194681c RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000427 R09: 000b6dc39dc3b368 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc51946c30 R13: 0000000000000004 R14: 00007ffc5194681c R15: 00007ffc519468b0