INFO: task syz.4.988:10389 blocked for more than 143 seconds.
Not tainted 6.14.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.988 state:D stack:27904 pid:10389 tgid:10386 ppid:8273 task_flags:0x400140 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0xf43/0x5890 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6857
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
__mutex_lock_common kernel/locking/mutex.c:662 [inline]
__mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730
nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629
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:2533
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338
netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:733 [inline]
____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
__sys_sendmsg+0x16e/0x220 net/socket.c:2659
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: 0033:0x7fb46b38d169
RSP: 002b:00007fb46c11e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb46b5a6080 RCX: 00007fb46b38d169
RDX: 0000000000000810 RSI: 0000400000002640 RDI: 0000000000000002
RBP: 00007fb46b40e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb46b5a6080 R15: 00007fff3848b1f8
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
2 locks held by syz.1.872/9889:
#0: ffffffff8ff9b110 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922
2 locks held by syz.4.988/10389:
#0: ffffffff8ff9b110 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.2.1089/10846:
#0: ffff88806413a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88806413a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88806413a0e0 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:505
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by syz.6.1334/12056:
#0: ffffffff8ff9b110 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.6.1334/12057:
#0: ffffffff8ff9b110 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1629
2 locks held by syz.0.1358/12224:
#0: ffffffff8ff9b110 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5c0548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922
1 lock held by syz.8.1362/12237:
#0: ffffffff8ee8a728 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xad/0xe0 drivers/tty/tty_io.c:1700
1 lock held by syz.9.1356/12288:
#0: ffffffff8ee8a728 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8ee8a728 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129
11 locks held by syz.7.1368/12295:
#0: ffff888027e50638 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1192
#1: ffff888035a2a420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731
#2: ffff888069a2e088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325
#3: ffff888143328f08 (kn->active#112){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x29e/0x500 fs/kernfs/file.c:326
#4: ffffffff8e1aaa40 (console_lock){+.+.}-{0:0}, at: store_fbstate+0xa5/0x110 drivers/video/fbdev/core/fbsysfs.c:333
#5: ffff888142b1c078 (&fb_info->lock){+.+.}-{4:4}, at: lock_fb_info include/linux/fb.h:626 [inline]
#5: ffff888142b1c078 (&fb_info->lock){+.+.}-{4:4}, at: store_fbstate+0xb3/0x110 drivers/video/fbdev/core/fbsysfs.c:334
#6: ffff888144ee6280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_pan_display+0xd6/0x9b0 drivers/gpu/drm/drm_fb_helper.c:1432
#7: ffff888024ee41b0 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x21/0x80 drivers/gpu/drm/drm_auth.c:452
#8: ffff888144ee6098 (&client->modeset_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_locked+0x4c/0x580 drivers/gpu/drm/drm_client_modeset.c:1180
#9: ffffc90004ae7700 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0xc9/0x7f0 drivers/gpu/drm/drm_client_modeset.c:1018
#10: ffffc90004ae7728 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_atomic+0xc9/0x7f0 drivers/gpu/drm/drm_client_modeset.c:1018
1 lock held by init/12300:
#0: ffffffff8ee8a728 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8ee8a728 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__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:236 [inline]
watchdog+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>