INFO: task syz.1.319:6242 blocked for more than 148 seconds. Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.319 state:D stack:26560 pid:6242 tgid:6235 ppid:5857 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 rpc_wait_bit_killable+0x17/0x170 net/sunrpc/sched.c:279 __wait_on_bit+0x62/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xda/0x110 kernel/sched/wait_bit.c:64 __rpc_execute+0x556/0x1230 net/sunrpc/sched.c:987 rpc_execute+0x2f8/0x430 net/sunrpc/sched.c:1025 rpc_run_task+0x530/0x750 net/sunrpc/clnt.c:1250 rpc_call_sync+0xca/0x1b0 net/sunrpc/clnt.c:1279 rpcb_register_call net/sunrpc/rpcb_clnt.c:412 [inline] rpcb_register+0x22a/0x4f0 net/sunrpc/rpcb_clnt.c:476 __svc_unregister net/sunrpc/svc.c:1203 [inline] svc_unregister+0x4fe/0x740 net/sunrpc/svc.c:1231 svc_rpcb_setup net/sunrpc/svc.c:429 [inline] svc_bind+0x1bb/0x210 net/sunrpc/svc.c:462 nfsd_create_serv+0x268/0x430 fs/nfsd/nfssvc.c:669 nfsd_nl_listener_set_doit+0xeb/0x1b20 fs/nfsd/nfsctl.c:1958 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0xab5/0xc90 net/socket.c:2597 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2651 __sys_sendmsg+0x117/0x1f0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f441e379e79 RSP: 002b:00007f441f168038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f441e516130 RCX: 00007f441e379e79 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007f441e3e7916 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f441e516130 R15: 00007ffde40b9648 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8ddb5be0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6626 2 locks held by getty/4971: #0: ffff88802b0a50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:4/5270: #0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc90003e0fd80 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 2 locks held by syz.1.319/6242: #0: ffffffff8fac0930 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1b51c8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0xe3/0x1b20 fs/nfsd/nfsctl.c:1956 2 locks held by syz.2.402/6516: #0: ffffffff8fac0930 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1b51c8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0xe3/0x1b20 fs/nfsd/nfsctl.c:1956 1 lock held by syz-executor/6572: #0: ffffffff8ddc1378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 2 locks held by syz.4.427/6733: #0: ffffffff8fac0930 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1b51c8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0xe3/0x1b20 fs/nfsd/nfsctl.c:1956 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6143 Comm: syz.3.285 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:lookup_page_ext mm/page_ext.c:252 [inline] RIP: 0010:page_ext_get+0x123/0x310 mm/page_ext.c:526 Code: 98 ff 83 e5 7f 48 c1 e5 05 4c 01 e5 e8 b6 ba 98 ff 48 8d 7d 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 bb 01 00 00 4c 8b 65 10 e8 0e 20 7e ff 31 ff 89 c5 89 c6 e8 RSP: 0018:ffffc9000334f980 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 000000000006bf10 RCX: ffffffff81f1bd64 RDX: 1ffff11027fff236 RSI: ffffffff81f1bdea RDI: ffff88813fff91b0 RBP: ffff88813fff91a0 R08: 0000000000000007 R09: 000000000007ffff R10: 000000000000000d R11: 0000000000000000 R12: ffff88813fff9000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc0d882ec0 CR3: 000000002ec30000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __page_table_check_zero+0xcd/0x370 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1095 [inline] free_unref_page+0x659/0xe40 mm/page_alloc.c:2612 vfree+0x181/0x7a0 mm/vmalloc.c:3364 kcov_put kernel/kcov.c:438 [inline] kcov_put+0x2a/0x40 kernel/kcov.c:434 kcov_close+0x10/0x20 kernel/kcov.c:534 __fput+0x408/0xbb0 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xaa3/0x2bb0 kernel/exit.c:882 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fd/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f086df79e79 Code: Unable to access opcode bytes at 0x7f086df79e4f. RSP: 002b:00007f086ed39038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000014 RBX: 00007f086e116130 RCX: 00007f086df79e79 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007f086dfe7916 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f086e116130 R15: 00007ffd53dadae8 vkms_vblank_simulate: vblank timer overrun