INFO: task syz-executor:5826 blocked for more than 142 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23336 pid:5826 tgid:5826 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1347
deactivate_locked_super+0xc1/0x1a0 fs/super.c:473
deactivate_super fs/super.c:506 [inline]
deactivate_super+0xde/0x100 fs/super.c:502
cleanup_mnt+0x225/0x450 fs/namespace.c:1318
task_work_run+0x150/0x240 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45c3b90a77
RSP: 002b:00007fff8d6dd538 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f45c3c13d7d RCX: 00007f45c3b90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff8d6de680
RBP: 00007fff8d6de66c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff8d6de680
R13: 00007f45c3c13d7d R14: 0000000000028183 R15: 00007fff8d6de6c0
INFO: task syz.0.267:6960 blocked for more than 163 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.267 state:D stack:27672 pid:6960 tgid:6959 ppid:5827 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2030
genl_family_rcv_msg_doit+0x209/0x2f0 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+0x5aa/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
__sys_sendmsg+0x16d/0x220 net/socket.c:2716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d5038f749
RSP: 002b:00007f1d5130b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1d505e5fa0 RCX: 00007f1d5038f749
RDX: 0000000000008000 RSI: 0000200000001240 RDI: 0000000000000005
RBP: 00007f1d50413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d505e6038 R14: 00007f1d505e5fa0 R15: 00007fff7e649148
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
#0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc900000f7d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff8e3cfa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820
1 lock held by khungtaskd/31:
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/5590:
#0: ffff8880345e90a0 (&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-executor/5826:
#0: ffff8880291ac0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880291ac0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880291ac0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880291ac0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz-executor/5829:
#0: ffff88807ee500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807ee500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807ee500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff88807ee500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
4 locks held by kworker/u10:0/6628:
#0: ffff88801ba9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc9000473fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff900d4e90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669
#3: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.3.263/6946:
#0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590
2 locks held by syz.0.267/6960:
#0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2030
2 locks held by syz-executor/7363:
#0: ffff888034b4c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888034b4c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888034b4c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff888034b4c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz.5.442/8016:
#0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2030
2 locks held by syz-executor/8109:
#0: ffff8880591500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880591500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880591500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880591500e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
2 locks held by syz.6.466/8143:
#0: ffffffff9018f090 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x13e/0x7b0 fs/nfsd/nfsctl.c:2030
2 locks held by syz-executor/8368:
#0: ffff8880689460e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880689460e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880689460e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline]
#0: ffff8880689460e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502
#1: ffffffff8e7ed348 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593
3 locks held by syz.7.775/9501:
4 locks held by syz.7.775/9510:
=============================================
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 10/25/2025
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:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
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: 9501 Comm: syz.7.775 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:update_hashtables lib/842/842_compress.c:436 [inline]
RIP: 0010:sw842_compress+0x1472/0x46b0 lib/842/842_compress.c:552
Code: 80 68 d0 00 00 00 00 00 00 48 c7 80 70 d0 00 00 00 00 00 00 e8 1f ec 11 fd 48 8b 4c 24 68 48 89 c8 48 c1 e8 03 42 0f b6 14 28 <48> 89 c8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 0e 29 00 00 4a
RSP: 0018:ffffc90002ed5700 EFLAGS: 00000a03
RAX: 1ffff11029bcc008 RBX: 00000000000001e6 RCX: ffff88814de60046
RDX: 0000000000000000 RSI: ffffffff84aa6b61 RDI: ffff88814de6e730
RBP: ffff88814de6e730 R08: 0000000000000001 R09: 0000000000000bc0
R10: ffff88814de6e728 R11: ffff88814de60030 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000000000f3 R15: ffff88814de60000
FS: 00007f41b19886c0(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f41b19679a0 CR3: 000000007e576000 CR4: 00000000003526f0
Call Trace:
crypto_scomp_decompress include/crypto/internal/scompress.h:79 [inline]
scomp_acomp_comp_decomp+0x719/0xd20 crypto/scompress.c:256
crypto_acomp_compress+0x14c/0x520 crypto/acompress.c:291
zswap_compress mm/zswap.c:886 [inline]
zswap_store_page mm/zswap.c:1429 [inline]
zswap_store+0xab3/0x2830 mm/zswap.c:1540
swap_writeout+0x3f4/0x1090 mm/page_io.c:275
shmem_writeout+0xc29/0x1140 mm/shmem.c:1642
writeout mm/vmscan.c:660 [inline]
pageout mm/vmscan.c:721 [inline]
shrink_folio_list+0x2f45/0x4800 mm/vmscan.c:1453
evict_folios+0x79c/0x1b30 mm/vmscan.c:4745
try_to_shrink_lruvec+0x585/0x9b0 mm/vmscan.c:4908
lru_gen_shrink_lruvec mm/vmscan.c:5057 [inline]
shrink_lruvec+0x312/0x2b00 mm/vmscan.c:5818
shrink_node_memcgs mm/vmscan.c:6054 [inline]
shrink_node+0x982/0x3d80 mm/vmscan.c:6095
shrink_zones mm/vmscan.c:6339 [inline]
do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6401
try_to_free_mem_cgroup_pages+0x31b/0x790 mm/vmscan.c:6729
try_charge_memcg+0x42a/0xd30 mm/memcontrol.c:2356
try_charge mm/memcontrol.c:2498 [inline]
charge_memcg+0x8a/0x230 mm/memcontrol.c:4701
__mem_cgroup_charge+0x2b/0x1e0 mm/memcontrol.c:4718
mem_cgroup_charge include/linux/memcontrol.h:662 [inline]
shmem_alloc_and_add_folio+0x50c/0xc20 mm/shmem.c:1922
shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2535
shmem_get_folio mm/shmem.c:2641 [inline]
shmem_write_begin+0x160/0x300 mm/shmem.c:3291
generic_perform_write+0x3c4/0x900 mm/filemap.c:4254
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3466
__kernel_write_iter+0x31a/0xb10 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x413/0xb70 fs/coredump.c:1372
elf_core_dump+0x29c3/0x3c00 fs/binfmt_elf.c:2111
coredump_write fs/coredump.c:1049 [inline]
vfs_coredump+0x2b9f/0x5670 fs/coredump.c:1170
get_signal+0x22e1/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x176/0x310 kernel/entry/common.c:73
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x401000
Code: Unable to access opcode bytes at 0x400fd6.
RSP: 002b:000000000000000a EFLAGS: 00010282
RAX: 0000000000000002 RBX: 00007f41b0de6090 RCX: 00007f41b0b8f749
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007f41b0c13f91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f41b0de6128 R14: 00007f41b0de6090 R15: 00007ffc61d199f8