INFO: task syz.3.781:9032 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.781 state:D stack:26168 pid:9032 tgid:9025 ppid:5608 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:785 __sock_sendmsg net/socket.c:800 [inline] ____sys_sendmsg+0x565/0x870 net/socket.c:2702 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2756 __sys_sendmsg net/socket.c:2788 [inline] __do_sys_sendmsg net/socket.c:2793 [inline] __se_sys_sendmsg net/socket.c:2791 [inline] __x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2791 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd156edce59 RSP: 002b:00007fd1550f4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd157156180 RCX: 00007fd156edce59 RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007fd156f72e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd157156218 R14: 00007fd157156180 R15: 00007ffc6498e958 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc90000117c60 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 1 lock held by khungtaskd/38: #0: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 5 locks held by kworker/u8:7/180: #0: ffff88801b696138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000390fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f37ad00 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0 net/core/net_namespace.c:248 #4: ffff8880816d5978 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_exit_rtnl+0xab/0x200 drivers/net/wireguard/device.c:423 2 locks held by dhcpcd/5269: #0: ffff88804e768928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe7/0xee0 net/netlink/af_netlink.c:2273 #1: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14b0 net/core/rtnetlink.c:2562 2 locks held by getty/5365: #0: ffff88803650b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:16/7349: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc900042cfc60 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 3 locks held by kworker/u8:24/7360: #0: ffff888031c72138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc900043bfc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4229 2 locks held by syz.2.778/9012: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 2 locks held by syz.3.781/9032: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 2 locks held by syz.0.850/9556: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 2 locks held by syz.4.851/9562: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 2 locks held by syz.6.856/9596: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 2 locks held by syz.5.865/9647: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 1 lock held by udevd/9652: #0: ffff888037603a30 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_downgrade include/linux/mmap_lock.h:586 [inline] #0: ffff888037603a30 (&mm->mmap_lock){++++}-{4:4}, at: vms_complete_munmap_vmas+0x224/0xbe0 mm/vma.c:1340 2 locks held by syz.7.888/9885: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 1 lock held by syz-executor/10041: #0: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 2 locks held by syz.8.948/10279: #0: ffffffff8f3fafa0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8e2ebd78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x136/0x16e0 fs/nfsd/nfsctl.c:1964 1 lock held by syz-executor/10291: #0: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 2 locks held by syz-executor/10374: #0: ffffffff8f37ad00 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f38a038 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x820 net/ipv4/ip_tunnel.c:1149 2 locks held by syz.1.973/10412: #0: ffff888031c80500 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:538 #1: ffff88806b8a6648 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1029 [inline] #1: ffff88806b8a6648 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: chown_common+0x313/0x640 fs/open.c:764 7 locks held by syz.9.976/10420: #0: ffff88801b6c2500 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff88801b6c2500 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88806407ce90 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff88806407ce90 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3404 #2: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: inode_add_bytes+0x38/0x140 fs/stat.c:919 #3: ffff8880b8642ed8 (_T->lock){....}-{2:2}, at: rt_mutex_slowunlock+0xbf/0xa20 kernel/locking/rtmutex.c:1430 #4: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8dfc3080 (rcu_read_lock){....}-{1:3}, at: lruvec_stat_mod_folio+0x6e/0x3e0 mm/memcontrol.c:983 #5: ffff8880b8642668 (_T->lock){....}-{2:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffff8880b8642668 (_T->lock){....}-{2:2}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffff8880b8642668 (_T->lock){....}-{2:2}, at: get_non_dying_memcg_start mm/memcontrol.c:817 [inline] #5: ffff8880b8642668 (_T->lock){....}-{2:2}, at: mod_memcg_lruvec_state+0xd5/0x270 mm/memcontrol.c:947 #6: ffff88801ceca2b0 (_T->lock){....}-{2:2}, at: rt_mutex_slowunlock+0xbf/0xa20 kernel/locking/rtmutex.c:1430 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:158 [inline] sys_info+0x135/0x170 lib/sys_info.c:166 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 10420 Comm: syz.9.976 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:246 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4881 [inline] RIP: 0010:__lock_acquire+0x530/0x2ce0 kernel/locking/lockdep.c:5189 Code: 83 c3 28 41 89 c4 49 39 cf 0f 8d a4 00 00 00 49 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 52 73 dc 11 73 10 <48> 69 c0 c8 00 00 00 48 8d 88 d0 14 1e 93 eb 32 83 3d 59 03 e0 17 RSP: 0018:ffffc90005d874c8 EFLAGS: 00000007 RAX: 000000000000082e RBX: ffff88802a5c4a28 RCX: 00000000ffffffff RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8b33d16c R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8dfc3080 R12: ffffffffffffff05 R13: ffff88802a5c4a58 R14: ffff88802a5c3e00 R15: 0000000000000000 FS: 00007f9e948f66c0(0000) GS:ffff888125eca000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9e8d4d5000 CR3: 000000007fc1c000 CR4: 00000000003526f0 Call Trace: reacquire_held_locks+0x104/0x190 kernel/locking/lockdep.c:5387 __lock_release kernel/locking/lockdep.c:5576 [inline] lock_release+0x199/0x3c0 kernel/locking/lockdep.c:5891 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock include/linux/spinlock_rt.h:109 [inline] consume_stock mm/memcontrol.c:2104 [inline] try_charge_memcg+0x5b0/0x15b0 mm/memcontrol.c:2611 charge_memcg+0x19c/0x2b0 mm/memcontrol.c:5126 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:5143 mem_cgroup_charge include/linux/memcontrol.h:641 [inline] shmem_alloc_and_add_folio mm/shmem.c:1959 [inline] shmem_get_folio_gfp+0x81a/0x1c40 mm/shmem.c:2502 shmem_get_folio mm/shmem.c:2608 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3239 generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4358 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9e9665d68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f9e948f5da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f9e948f66c0 RCX: 00007f9e9665d68e RDX: 0000000001000000 RSI: 00007f9e8c4d6000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00007f9e948f5ee0 R14: 00007f9e948f5ea0 R15: 00007f9e8c4d6000