INFO: task syz.2.935:9736 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-01183-g894fbb55e60c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.935 state:D stack:26088 pid:9736 tgid:9735 ppid:5841 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 nfsd_nl_rpc_status_get_dumpit+0xd9/0x1280 fs/nfsd/nfsctl.c:1516 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1027 netlink_dump+0x651/0xe70 net/netlink/af_netlink.c:2309 __netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2424 genl_family_rcv_msg_dumpit+0x1e7/0x2c0 net/netlink/genetlink.c:1076 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline] genl_rcv_msg+0x5da/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa07f98e969 RSP: 002b:00007fa0808ab038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa07fbb5fa0 RCX: 00007fa07f98e969 RDX: 0000000004000810 RSI: 0000200000000180 RDI: 0000000000000005 RBP: 00007fa07fa10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa07fbb5fa0 R15: 00007ffd759568f8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5588: #0: ffff8880320880a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by kworker/u8:9/7830: #0: ffff88801aefe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aefe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90004de7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004de7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2eb0d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x8a0 net/core/net_namespace.c:662 #3: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12614 #4: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #4: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/u8:14/7842: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000b737c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b737c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by syz.4.648/8596: #0: ffffffff8f35dc30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e2139e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1923 3 locks held by syz.2.935/9736: #0: ffffffff8f35dc30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88805a58d6d0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2388 #2: ffffffff8e2139e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xd9/0x1280 fs/nfsd/nfsctl.c:1516 2 locks held by syz.5.1197/10802: #0: ffffffff8f35dc30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e2139e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1923 7 locks held by syz-executor/13647: #0: ffff88802f24a420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff88802f24a420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff88807f2d3488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888144ba72d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8eb977e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 #4: ffff8880463520e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff8880463520e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8880463520e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 #5: ffff888046354250 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2143 2 locks held by syz-executor/13682: #0: ffffffff8f7fafd0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7fafd0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f7fafd0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4065 2 locks held by syz.0.1947/13745: #0: ffffffff8f35dc30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e2139e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1923 2 locks held by syz.1.1963/13812: #0: ffffffff8f35dc30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e2139e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1923 1 lock held by syz.7.1969/13842: #0: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038 1 lock held by syz.7.1969/13843: #0: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6961 1 lock held by syz.7.1969/13844: #0: ffffffff8f2f7c88 (rtnl_mutex){+.+.}-{4:4}, at: tc_new_tfilter+0x4b5/0x15b0 net/sched/cls_api.c:2308 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-01183-g894fbb55e60c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7844 Comm: kworker/u8:15 Not tainted 6.15.0-rc6-syzkaller-01183-g894fbb55e60c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__kasan_check_byte+0x6/0x40 mm/kasan/common.c:555 Code: 89 c7 e9 dd fe ff ff 66 66 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 66 0f 1f 00 41 56 <53> 48 89 f3 49 89 fe e8 1e 12 00 00 84 c0 75 16 be 01 00 00 00 4c RSP: 0018:ffffc9000b497960 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 65ea784fb7447d00 RDX: 0000000000000000 RSI: ffffffff8b5aa986 RDI: ffff88804e8bc818 RBP: ffffffff8b267177 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1efeeaf R12: 0000000000000000 R13: ffff88804e8bc818 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881261b6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557dbd65c8 CR3: 0000000031972000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5840 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245