INFO: task kworker/u8:10:2574 blocked for more than 144 seconds. Not tainted 6.10.0-next-20240725-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:10 state:D stack:19856 pid:2574 tgid:2574 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 __schedule_loop kernel/sched/core.c:6680 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6695 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6752 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 write_inode fs/fs-writeback.c:1497 [inline] __writeback_single_inode+0x6b9/0x10b0 fs/fs-writeback.c:1716 writeback_sb_inodes+0x99c/0x1380 fs/fs-writeback.c:1947 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2018 wb_writeback+0x495/0xd40 fs/fs-writeback.c:2129 wb_check_background_flush fs/fs-writeback.c:2199 [inline] wb_do_writeback fs/fs-writeback.c:2287 [inline] wb_workfn+0xc58/0x1090 fs/fs-writeback.c:2314 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 4 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6695 2 locks held by kworker/u8:3/52: 3 locks held by kworker/1:2/58: #0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000123fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000123fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc82688 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 4 locks held by kworker/u8:10/2574: #0: ffff888018e84948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888018e84948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000955fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000955fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff88807ce220e0 (&type->s_umount_key#99){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88807ce240e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 1 lock held by dhcpcd/4894: #0: ffffffff8fc82688 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1101 2 locks held by getty/4980: #0: ffff88802b6cd0a0 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 ( &ldata->atomic_read_lock ){+.+.}-{3:3} , at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:4/5277: 3 locks held by kworker/u8:11/11117: #0: ffff88802ac95948 ( (wq_completion)ipv6_addrconf ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3206 [inline] , at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc900183efd00 ( (work_completion)(&(&net->ipv6.addr_chk_work)->work) ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3207 [inline] , at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc82688 ( rtnl_mutex ){+.+.}-{3:3} , at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/u8:14/11121: 2 locks held by syz.0.1836/11335: 4 locks held by udevd/11771: #0: ffff88802d2a5540 (&p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff888064094488 ( &of->mutex #2 ){+.+.}-{3:3} , at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989 #2: ffff88804817ad58 (&ep->lock){....}-{2:2}, at: ep_poll_callback+0xd2/0xb50 fs/eventpoll.c:1317 #3: ffff88804817aca8 (&ep->wq){....}-{2:2}, at: __wake_up_common_lock+0x25/0x1e0 kernel/sched/wait.c:105 7 locks held by syz-executor/15878: #0: ffff88802b58e420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline] #0: ffff88802b58e420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff88802fa66488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888023353b48 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8f51f608 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff888064eb40e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888064eb40e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 #5: ffff88805205f250 (&devlink->lock_key#21){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534 #6: ffffffff8fc82688 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:678 [inline] #6: ffffffff8fc82688 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x408/0x890 drivers/net/netdevsim/netdev.c:750 4 locks held by syz-executor/16344: #0: ffff88802b58e420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline] #0: ffff88802b58e420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff88802de2a088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888023353c38 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8f51f608 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 3 locks held by syz.4.2227/17599: #0: ffff8880631bca08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline] #0: ffff8880631bca08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff8880631bca08 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1421 #1: ffff88806e232258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #1: ffff88806e232258 (sk_lock-AF_PPPOX){+.+.}-{0:0}, at: pptp_release+0x52/0x300 drivers/net/ppp/pptp.c:508 #2: ffffffff8e93ce38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #2: ffffffff8e93ce38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:967 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-next-20240725-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11121 Comm: kworker/u8:14 Not tainted 6.10.0-next-20240725-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] RIP: 0010:arch_local_irq_enable arch/x86/include/asm/irqflags.h:97 [inline] RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:155 [inline] RIP: 0010:lock_acquire+0x25a/0x550 kernel/locking/lockdep.c:5825 Code: 00 00 9c 8f 44 24 60 42 80 3c 2b 00 74 08 4c 89 f7 e8 aa 9e 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 48 c7 44 24 40 0e 36 e0 45 4b c7 44 25 00 00 00 00 00 43 c7 44 RSP: 0018:ffffc900184e7940 EFLAGS: 00000006 RAX: 0000000000000001 RBX: 1ffff9200309cf34 RCX: f782ef9c38e2d300 RDX: dffffc0000000000 RSI: ffffffff8c0ae6c0 RDI: ffffffff8c607bc0 RBP: ffffc900184e7a90 R08: ffffffff937358df R09: 1ffffffff26e6b1b R10: dffffc0000000000 R11: fffffbfff26e6b1c R12: 1ffff9200309cf30 R13: dffffc0000000000 R14: ffffc900184e79a0 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0de9ab1d20 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe8/0x3b0 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:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 DEBUG: waiting rtnl_mutex for 943 jiffies. task:kworker/1:2 state:D stack:19000 pid:58 tgid:58 ppid:2 flags:0x00004000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 __schedule_loop kernel/sched/core.c:6680 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6695 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6752 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752