INFO: task syz.2.527:7961 blocked for more than 143 seconds. Not tainted 6.13.0-rc2-syzkaller-00333-ga0e3919a2df2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.527 state:D stack:27128 pid:7961 tgid:7960 ppid:5828 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x62b/0xa60 kernel/locking/mutex.c:735 nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1813 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+0x165/0x410 net/netlink/af_netlink.c:2542 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2583 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637 __sys_sendmsg+0x16e/0x220 net/socket.c:2669 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: 0033:0x7fe871185d19 RSP: 002b:00007fe871f0b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe871375fa0 RCX: 00007fe871185d19 RDX: 0000000000004010 RSI: 00000000200004c0 RDI: 0000000000000006 RBP: 00007fe871201a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe871375fa0 R15: 00007ffc374c0618 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 3 locks held by kworker/u8:7/1337: 2 locks held by getty/5589: #0: ffff8880314a70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5824: 2 locks held by syz.3.394/7468: #0: ffffffff8fb5c850 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1b9808 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1671 2 locks held by syz.2.527/7961: #0: ffffffff8fb5c850 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1b9808 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc5/0x7a0 fs/nfsd/nfsctl.c:1813 2 locks held by syz.0.570/8130: #0: ffff8880282a80e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880282a80e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880282a80e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1b9808 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz-executor/8314: #0: ffff88804b9940e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88804b9940e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88804b9940e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1b9808 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 1 lock held by syz.1.744/8877: #0: ffffffff8ddc6278 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 2 locks held by syz.4.1030/9956: #0: ffff8880494980e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880494980e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880494980e0 (&type->s_umount_key#51){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1b9808 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 3 locks held by syz-executor/10250: 3 locks held by syz.5.1152/10377: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc2-syzkaller-00333-ga0e3919a2df2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 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:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5824 Comm: syz-executor Not tainted 6.13.0-rc2-syzkaller-00333-ga0e3919a2df2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x70 kernel/kcov.c:217 Code: cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 44 9c 6a 7e <65> 8b 05 45 9c 6a 7e a9 00 01 ff 00 48 8b 34 24 74 1d f6 c4 01 74 RSP: 0018:ffffc900038ff980 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff82074753 RDX: ffff888071171e00 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88801e4a2170 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff88801e4a216c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31ef3ff8 CR3: 000000000db7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0x30/0xd0 mm/page_ext.c:550 __page_table_check_zero+0x2d7/0x360 mm/page_table_check.c:160 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1128 [inline] free_unref_page+0x6c8/0x1080 mm/page_alloc.c:2657 vfree+0x17a/0x890 mm/vmalloc.c:3382 kcov_put kernel/kcov.c:439 [inline] kcov_put+0x2a/0x40 kernel/kcov.c:435 kcov_close+0xd/0x20 kernel/kcov.c:535 __fput+0x3f8/0xb60 fs/file_table.c:450 task_work_run+0x14e/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xadd/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x2576/0x2610 kernel/signal.c:3017 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [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: 0033:0x7fc81c57bf53 Code: Unable to access opcode bytes at 0x7fc81c57bf29. RSP: 002b:00007ffedbb3c2b8 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000016c5 RCX: 00007fc81c57bf53 RDX: 0000000040000000 RSI: 00007ffedbb3c2cc RDI: 00000000ffffffff RBP: 00007ffedbb3c2cc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000