INFO: task syz.2.679:9133 blocked for more than 144 seconds. Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.679 state:D stack:21976 pid:9133 tgid:9133 ppid:8472 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 eventpoll_release include/linux/eventpoll.h:53 [inline] __fput+0x6e0/0x8a0 fs/file_table.c:413 task_work_run+0x251/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8528d79eb9 RSP: 002b:00007ffdd12a0528 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f8528f17a80 RCX: 00007f8528d79eb9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8528f17a80 R08: 0000000000000006 R09: 00007ffdd12a081f R10: 00000000003ffcf4 R11: 0000000000000246 R12: 0000000000061e87 R13: 00007ffdd12a0630 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 2 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 5 locks held by kworker/u8:4/62: #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc900015d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc900015d7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc7f190 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594 #3: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xa90 net/core/dev.c:11883 #4: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #4: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958 3 locks held by kworker/u8:6/1101: #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90004357d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90004357d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by dhcpcd/4896: #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 2 locks held by getty/4991: #0: ffff88823bd208a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:12/5411: 1 lock held by syz.2.679/9133: #0: ffff88802c395468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 3 locks held by syz.2.679/9134: 1 lock held by syz-executor/10158: #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline] #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958 1 lock held by syz-executor/10556: #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 4 locks held by syz.3.945/10629: #0: ffff88802ad60420 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88805eca2e90 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:835 [inline] #1: ffff88805eca2e90 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:3979 #2: ffffffff8e965ea8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:367 [inline] #2: ffffffff8e965ea8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe6/0x290 kernel/cgroup/cgroup.c:1662 #3: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: cgrp_css_online+0x90/0x2f0 net/core/netprio_cgroup.c:157 1 lock held by syz.3.945/10632: #0: ffff88807d54c868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_write+0xd60/0x1a40 fs/pipe.c:580 2 locks held by syz.3.945/10633: #0: ffff88807d54c868 (&pipe->mutex){+.+.}-{3:3}, at: splice_to_socket+0xee/0x10b0 fs/splice.c:809 #1: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 1 lock held by syz.0.942/10635: #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 1 lock held by syz-executor/10636: #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fc8bd48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5299 Comm: kworker/1:3 Not tainted 6.11.0-rc6-syzkaller-00019-g67784a74e258 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x90 kernel/kcov.c:312 Code: 10 48 89 74 0a 18 4c 89 44 0a 20 e9 35 b0 5c 0a 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 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 00 d7 03 00 65 8b 05 00 46 RSP: 0018:ffffc900047a7650 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc900047a76c8 RCX: ffffffff9175a000 RDX: ffffffff918f8401 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff814125c7 R09: ffffffff814140bf R10: 0000000000000003 R11: ffff8880612fbc00 R12: ffff8880612fbc00 R13: ffffffff817f2f80 R14: dffffc0000000000 R15: 1ffff920008f4ed9 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020008040 CR3: 000000004aa7c000 CR4: 0000000000350ef0 Call Trace: unwind_get_return_address+0x68/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 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:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kmem_cache_free+0x145/0x350 mm/slub.c:4548 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244