INFO: task syz-executor.4:5894 blocked for more than 143 seconds. Not tainted 6.3.0-rc2-next-20230317-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:26728 pid:5894 ppid:5142 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5305 [inline] __schedule+0x1d23/0x5650 kernel/sched/core.c:6623 schedule+0xde/0x1a0 kernel/sched/core.c:6699 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6758 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747 eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 eventpoll_release include/linux/eventpoll.h:53 [inline] __fput+0x7da/0xa90 fs/file_table.c:312 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x25b0 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f8bad28c0f9 RSP: 002b:00007f8bae094168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: 0000000000009e00 RBX: 00007f8bad3abf80 RCX: 00007f8bad28c0f9 RDX: 000000000000ff2e RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007f8bad2e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe2aaced5f R14: 00007f8bae094300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c795830 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c795530 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/28: #0: ffffffff8c796400 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545 2 locks held by getty/4762: #0: ffff888027517098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177 1 lock held by syz-executor.2/5145: #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:992 2 locks held by kworker/1:4/5202: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc90004a3fda8 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 1 lock held by syz-executor.4/5894: #0: ffff88801fe00068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 1 lock held by syz-executor.4/5901: 3 locks held by syz-executor.1/8611: #0: ffff88808dd61410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:761 [inline] #0: ffff88808dd61410 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release+0x86/0x290 net/socket.c:652 #1: ffff888087123130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1697 [inline] #1: ffff888087123130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x203/0xa40 net/can/bcm.c:1523 #2: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #2: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e8/0x770 kernel/rcu/tree_exp.h:992 1 lock held by syz-executor.4/8614: #0: ffffffff8e103488 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x17c/0x240 drivers/net/ppp/ppp_generic.c:405 1 lock held by syz-executor.5/8628: #0: ffff88814b93e460 (sb_writers#4){.+.+}-{0:0}, at: mmap_read_lock include/linux/mmap_lock.h:142 [inline] #0: ffff88814b93e460 (sb_writers#4){.+.+}-{0:0}, at: exit_mmap+0xec/0x930 mm/mmap.c:3043 1 lock held by syz-executor.0/8625: #0: ffffffff8d6aaa48 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x9a/0x2510 drivers/net/ppp/ppp_generic.c:712 2 locks held by syz-executor.3/8626: #0: ffffffff8d6aaa48 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x9a/0x2510 drivers/net/ppp/ppp_generic.c:712 #1: ffffffff8e103488 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3331 [inline] #1: ffffffff8e103488 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1043 [inline] #1: ffffffff8e103488 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x1625/0x2510 drivers/net/ppp/ppp_generic.c:716 1 lock held by syz-executor.3/8629: #0: ffffffff8d6aaa48 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x9a/0x2510 drivers/net/ppp/ppp_generic.c:712 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc2-next-20230317-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x33e/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8634 Comm: syz-executor.5 Not tainted 6.3.0-rc2-next-20230317-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:207 Code: 81 e1 00 01 00 00 65 48 8b 14 25 00 bb 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 64 15 00 00 85 c0 74 2b 8b 82 40 15 00 00 <83> f8 02 75 20 48 8b 8a 48 15 00 00 8b 92 44 15 00 00 48 8b 01 48 RSP: 0018:ffffc900056ef870 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000000 RDX: ffff88807d511d40 RSI: ffffffff88bf0b57 RDI: 0000000000000006 RBP: ffff88807ab3e3c0 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808fa35800 R13: ffff88808fa35d28 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f074a7c5700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200ae030 CR3: 0000000029e2e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unix_dgram_recvmsg+0x3e7/0xb90 net/unix/af_unix.c:2491 unix_dgram_recvmsg+0xc4/0xf0 net/unix/af_unix.c:2549 sock_recvmsg_nosec net/socket.c:1017 [inline] ____sys_recvmsg+0x49c/0x5a0 net/socket.c:2718 ___sys_recvmsg+0xf2/0x180 net/socket.c:2762 do_recvmmsg+0x25e/0x6e0 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0749a8c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f074a7c5168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f0749bac050 RCX: 00007f0749a8c0f9 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f0749ae7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca63358ef R14: 00007f074a7c5300 R15: 0000000000022000