INFO: task syz.3.1802:12563 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1802 state:D stack:26704 pid:12563 tgid:12552 ppid:5850 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919
genl_family_rcv_msg_doit+0x206/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmsg+0x16d/0x220 net/socket.c:2700
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7effdbf8eba9
RSP: 002b:00007effdcdcc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007effdc1d6360 RCX: 00007effdbf8eba9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 000000000000000b
RBP: 00007effdc011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007effdc1d63f8 R14: 00007effdc1d6360 R15: 00007ffef3b00478
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/5607:
#0: ffff88814d78e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.4.1304/10577:
#0: ffffffff90428590 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9dabe8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919
2 locks held by syz.3.1802/12563:
#0: ffffffff90428590 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9dabe8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919
6 locks held by syz.6.2200/14065:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf0e/0x1260 kernel/hung_task.c:491
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14065 Comm: syz.6.2200 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:unwind_next_frame+0x4f3/0x20a0 arch/x86/kernel/unwind_orc.c:505
Code: 44 24 28 48 8b 74 24 20 48 8b 44 24 18 8b 90 b8 03 00 00 4c 89 f9 4c 89 c7 e8 19 f1 ff ff 48 89 c1 48 85 c0 0f 84 05 fe ff ff <48> b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f
RSP: 0018:ffffc90003dbecf8 EFLAGS: 00000286
RAX: ffffffff914e7544 RBX: 0000000000000001 RCX: ffffffff914e7544
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff90c57260
RBP: ffffc90003dbedb0 R08: ffffffff914e7550 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000011509 R12: ffffc90003dbedb8
R13: ffffc90003dbed68 R14: ffffc90003dbed9d R15: ffffffff82150980
FS: 00007f45b5c0e6c0(0000) GS:ffff8881246b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000005321f000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__set_page_owner+0x91/0x550 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2435
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1908
shmem_alloc_and_add_folio+0x499/0xc20 mm/shmem.c:1947
shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2597
shmem_fault+0x1fe/0xa30 mm/shmem.c:2798
__do_fault+0x10d/0x490 mm/memory.c:5152
do_read_fault mm/memory.c:5573 [inline]
do_fault mm/memory.c:5707 [inline]
do_pte_missing+0xf50/0x3ba0 mm/memory.c:4234
handle_pte_fault mm/memory.c:6052 [inline]
__handle_mm_fault+0x152a/0x2a50 mm/memory.c:6195
handle_mm_fault+0x589/0xd10 mm/memory.c:6364
faultin_page mm/gup.c:1144 [inline]
__get_user_pages+0x551/0x34a0 mm/gup.c:1446
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1880
__mm_populate+0x1d8/0x380 mm/gup.c:1983
mm_populate include/linux/mm.h:3367 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:585
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45b4d8eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f45b5c0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f45b4fd6180 RCX: 00007f45b4d8eba9
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f45b4e11e19 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f45b4fd6218 R14: 00007f45b4fd6180 R15: 00007ffd40c25108