INFO: task syz-executor:5826 blocked for more than 143 seconds. Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20088 pid:5826 tgid:5826 ppid:1 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b9a/0x5250 kernel/sched/core.c:6769 __schedule_loop kernel/sched/core.c:6847 [inline] schedule+0x163/0x360 kernel/sched/core.c:6862 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6919 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 netdev_run_todo+0x380/0xf30 net/core/dev.c:11334 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3390 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x754/0x2520 kernel/exit.c:949 do_group_exit+0x207/0x2c0 kernel/exit.c:1098 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b1e3833d7 RSP: 002b:00007ffc933c47f0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: 000000000000017b RBX: 000000000000017b RCX: 00007f5b1e3833d7 RDX: 0000000040000001 RSI: 00007ffc933c485c RDI: 00000000ffffffff RBP: 00007ffc933c485c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388 R13: 00000000000927c0 R14: 0000000000042e4e R15: 00007ffc933c48b0 INFO: task syz-executor:5840 blocked for more than 144 seconds. Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20520 pid:5840 tgid:5840 ppid:1 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b9a/0x5250 kernel/sched/core.c:6769 __schedule_loop kernel/sched/core.c:6847 [inline] schedule+0x163/0x360 kernel/sched/core.c:6862 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6919 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 netdev_run_todo+0x380/0xf30 net/core/dev.c:11334 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3390 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x754/0x2520 kernel/exit.c:949 do_group_exit+0x207/0x2c0 kernel/exit.c:1098 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe02c5833d7 RSP: 002b:00007ffc266b5fe0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000000175 RCX: 00007fe02c5833d7 RDX: 0000000040000000 RSI: 00007ffc266b604c RDI: 00000000ffffffff RBP: 00007ffc266b604c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000074 R13: 000055557d1d5570 R14: 0000000000000005 R15: 00007ffc266b60a0 INFO: task syz-executor:7275 blocked for more than 145 seconds. Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20352 pid:7275 tgid:7275 ppid:1 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b9a/0x5250 kernel/sched/core.c:6769 __schedule_loop kernel/sched/core.c:6847 [inline] schedule+0x163/0x360 kernel/sched/core.c:6862 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6919 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 netdev_run_todo+0x380/0xf30 net/core/dev.c:11334 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3390 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x754/0x2520 kernel/exit.c:949 do_group_exit+0x207/0x2c0 kernel/exit.c:1098 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f52dd9833d7 RSP: 002b:00007ffcc3eff1c0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000007d RCX: 00007f52dd9833d7 RDX: 0000000040000000 RSI: 00007ffcc3eff22c RDI: 00000000ffffffff RBP: 00007ffcc3eff22c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000024 R13: 000055555d32f570 R14: 0000000000040e70 R15: 00007ffcc3eff280 INFO: task syz.2.584:8505 blocked for more than 146 seconds. Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.584 state:D stack:24840 pid:8505 tgid:8504 ppid:5825 task_flags:0x40054c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b9a/0x5250 kernel/sched/core.c:6769 __schedule_loop kernel/sched/core.c:6847 [inline] schedule+0x163/0x360 kernel/sched/core.c:6862 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6919 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 netdev_run_todo+0x380/0xf30 net/core/dev.c:11334 tun_detach drivers/net/tun.c:639 [inline] tun_chr_close+0x137/0x1b0 drivers/net/tun.c:3390 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x754/0x2520 kernel/exit.c:949 do_group_exit+0x207/0x2c0 kernel/exit.c:1098 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf4798d169 RSP: 002b:00007fdf48740038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: fffffffffffffffe RBX: 00007fdf47ba5fa0 RCX: 00007fdf4798d169 RDX: 0000200000000340 RSI: 00002000000000c0 RDI: 0000000000000000 RBP: 00007fdf47a0e990 R08: 0000200000000100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdf47ba5fa0 R15: 00007ffdf57cc888 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: 5 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8ed3f180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3f180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3f180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 4 locks held by kworker/u8:5/64: #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000156fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000156fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900f6710 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 2 locks held by kworker/1:2/3492: 2 locks held by getty/5580: #0: ffff88814d73b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5826: #0: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 1 lock held by syz-executor/5840: #0: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 1 lock held by syz-executor/7275: #0: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 1 lock held by syz.2.584/8505: #0: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 1 lock held by syz.3.578/8507: #0: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 4 locks held by syz-executor/8525: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88807ed3e088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8531: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88807b46ac88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8537: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88803210f488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 7 locks held by syz-executor/8539: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff8880803d4888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 #4: ffff88805bd5f0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88805bd5f0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88805bd5f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88805bed0250 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8ed44580 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3752 4 locks held by syz-executor/8703: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88814ea3f088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8715: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff8880809a9088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8718: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88806928ec88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8730: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff888081bc0c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8733: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88803fb34c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 3 locks held by kworker/1:9/8748: 4 locks held by syz-executor/8761: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88807fc9e888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8773: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff8880809cdc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8774: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88808bcfdc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8788: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff88807bf59888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 4 locks held by syz-executor/8789: #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3045 [inline] #0: ffff888033fbc428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff888098f15c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff88802751e698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f99c888 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 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: 61 Comm: kworker/1:1 Not tainted 6.15.0-rc1-next-20250411-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_long defense_work_handler RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:-1 [inline] RIP: 0010:rcu_is_watching+0x44/0xb0 kernel/rcu/tree.c:736 Code: 73 7a 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 60 6c 7a 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 dc d7 84 00 <48> c7 c3 58 2f 6b 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 RSP: 0018:ffffc90000a07668 EFLAGS: 00000246 RAX: 1ffffffff1cf4d8d RBX: 0000000000000001 RCX: ffff88801dafbc00 RDX: dffffc0000000000 RSI: ffffffff8ca1ee20 RDI: ffffffff8ca1ede0 RBP: dffffc0000000001 R08: ffffc9000153f8d0 R09: 0000000000000000 R10: ffffc90000a077b0 R11: fffff52000140ef8 R12: ffffc90000a07760 R13: dffffc0000000000 R14: ffffffff8e7a6c68 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff3b5729108 CR3: 000000000eb3a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1a5b/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kfree+0x198/0x430 mm/slub.c:4845 nf_conntrack_free+0x2ee/0x390 net/netfilter/nf_conntrack_core.c:1728 nf_ct_put include/net/netfilter/nf_conntrack.h:186 [inline] nf_conntrack_in+0xb56/0x18c0 net/netfilter/nf_conntrack_core.c:2055 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook+0x2c9/0x460 include/linux/netfilter.h:269 __ip_local_out+0x50f/0x610 net/ipv4/ip_output.c:118 ip_local_out+0x26/0x70 net/ipv4/ip_output.c:127 synproxy_send_client_synack+0x8ea/0xf70 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3cc/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x36a/0xa90 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x4b2/0x1db0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x41f/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29b/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a0/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5939 [inline] __netif_receive_skb+0x2c9/0x670 net/core/dev.c:6052 process_backlog+0x664/0x15c0 net/core/dev.c:6404 __napi_poll+0xcb/0x480 net/core/dev.c:7376 napi_poll net/core/dev.c:7440 [inline] net_rx_action+0x89d/0x1240 net/core/dev.c:7562 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 do_softirq+0x11f/0x1e0 kernel/softirq.c:480 __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] update_defense_level+0x8ee/0xcf0 net/netfilter/ipvs/ip_vs_ctl.c:210 defense_work_handler+0x22/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 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