INFO: task syz-executor:24455 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21456 pid:24455 tgid:24455 ppid:1 task_flags:0x40054c flags:0x00080003 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 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 netdev_run_todo+0x2ff/0x12a0 net/core/dev.c:11724 tun_detach drivers/net/tun.c:647 [inline] tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3506 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0259c8d68e RSP: 002b:00007ffdd19084d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 0000000000000028 RBX: 000055556c3cb500 RCX: 00007f0259c8d68e RDX: 0000000000000028 RSI: 00007f025aa74670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffdd1908554 R09: 000000000000000c RBP: 0000000000000001 R08: 00007ffdd1908554 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f025aa74670 R15: 0000000000000000 INFO: task syz.6.3105:24564 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.3105 state:D stack:24664 pid:24564 tgid:24564 ppid:22071 task_flags:0x40044c flags:0x00080003 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 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 netdev_run_todo+0x2ff/0x12a0 net/core/dev.c:11724 tun_detach drivers/net/tun.c:647 [inline] tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3506 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f089569ce59 RSP: 002b:00007ffeb91e56d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f0895917da0 RCX: 00007f089569ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f0895917da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00000000005ee630 R11: 0000000000000246 R12: 00000000001a13ba R13: 00007f089591609c R14: 00000000001a1128 R15: 00007ffeb91e57e0 Showing all locks held in the system: 4 locks held by rcuc/1/29: #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x261/0xc50 net/core/dev.c:6670 #2: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:242 [inline] #2: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0 include/linux/netfilter.h:316 #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 1 lock held by khungtaskd/38: #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 9 locks held by kworker/1:2/953: #0: ffff88813fe4b138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc900060ffc60 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #3: ffff8880b87241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff8880b87241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_lock_callback kernel/softirq.c:881 [inline] #3: ffff8880b87241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_action_common+0xc5/0x600 kernel/softirq.c:931 #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #5: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: ieee80211_rx_napi+0xd1/0x3d0 net/mac80211/rx.c:5710 #6: ffffffff8de591a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #7: ffff8880610a1d10 (&local->rx_path_lock){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline] #7: ffff8880610a1d10 (&local->rx_path_lock){+...}-{3:3}, at: ieee80211_rx_handlers+0x120/0xc8d0 net/mac80211/rx.c:4243 #8: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #8: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #8: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 2 locks held by getty/5363: #0: ffff8880322d20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5594: #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: aa_file_perm+0x18b/0x1600 security/apparmor/file.c:637 2 locks held by kworker/u8:26/12741: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000a4efc60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 4 locks held by kworker/u8:27/12742: #0: ffff88801b696138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc90007a6fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f378900 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffffffff8dfc9230 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz-executor/24455: #0: ffffffff8dfc9230 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz.6.3105/24564: #0: ffffffff8dfc9230 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 1 lock held by syz.1.3107/24573: #0: ffffffff8dfc9230 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 4 locks held by syz-executor/24631: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88803b2af478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24639: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88805e317478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24644: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff8880311fb878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 7 locks held by syz-executor/24653: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888062ff4878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803dec5160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff88803dec5160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88803dec5160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff88803f94e310 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8dfc9230 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857 4 locks held by syz-executor/24671: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff8880637d9878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24794: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888029d70878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24807: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888060170478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24820: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff8880543b4878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24848: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888025544078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 4 locks held by syz-executor/24870: #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff888035b90500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff888054039878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888028fac2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 ============================================= NMI backtrace for cpu 0 CPU: 0 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:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 29 Comm: rcuc/1 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:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d d4 17 cb 0b 48 89 de 5b e9 43 76 60 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 78 a7 af 10 65 8b 35 99 a7 af RSP: 0000:ffffc90000a3e8b8 EFLAGS: 00000287 RAX: ffffffff890ada09 RBX: 000000000009e640 RCX: ffff88801de93e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100 RBP: ffffc90000a3ea50 R08: 0000000000000000 R09: 0000000000000100 R10: ffffc90000a3e820 R11: fffff52000147d08 R12: e00000000cb77e9b R13: e00000000cb77e9a R14: 1ffffffff3488164 R15: e00000000cb77e9a FS: 0000000000000000(0000) GS:ffff888125fd4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055aa5fc52190 CR3: 000000000ddb0000 CR4: 00000000003526f0 Call Trace: save_dst_trace_buffer+0x1e0/0x5b0 net/core/dst.c:104 dst_init+0x255/0x490 net/core/dst.c:146 dst_alloc+0x12a/0x170 net/core/dst.c:171 rt_dst_alloc net/ipv4/route.c:1649 [inline] __mkroute_output net/ipv4/route.c:2652 [inline] ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2872 ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2702 __ip_route_output_key include/net/route.h:169 [inline] ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2929 ip_route_output_key include/net/route.h:179 [inline] ip_route_me_harder+0x762/0xfe0 net/ipv4/netfilter.c:54 synproxy_send_tcp+0x347/0x670 net/netfilter/nf_synproxy_core.c:434 synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4+0x37b/0x530 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6207 [inline] __netif_receive_skb net/core/dev.c:6320 [inline] process_backlog+0x564/0xc50 net/core/dev.c:6671 __napi_poll+0xae/0x550 net/core/dev.c:7730 napi_poll net/core/dev.c:7793 [inline] net_rx_action+0x621/0xd70 net/core/dev.c:7950 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch kernel/rcu/tree.c:2664 [inline] rcu_core kernel/rcu/tree.c:2897 [inline] rcu_cpu_kthread+0x99f/0x1480 kernel/rcu/tree.c:2985 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 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