INFO: task syz.4.421:9468 blocked for more than 143 seconds. Not tainted 6.10.0-syzkaller-01155-gd67978318827 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.421 state:D stack:22008 pid:9468 tgid:9468 ppid:8792 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5407 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6748 __schedule_loop kernel/sched/core.c:6825 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6840 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6897 __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+0x24f/0x310 kernel/task_work.c:180 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: 0033:0x7fbeff775bd9 RSP: 002b:00007ffe9872f6f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fbeff905a60 RCX: 00007fbeff775bd9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fbeff905a60 R08: 0000000000000006 R09: 0000000d9872fa1f R10: 00000000003ffcec R11: 0000000000000246 R12: 000000000005b54b R13: 0000000000000032 R14: 00007fbeff905a60 R15: 00007fbeff904038 Showing all locks held in the system: 2 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 5 locks held by kworker/u8:6/1060: 3 locks held by kworker/u8:8/2829: #0: ffff88802a45a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88802a45a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90009e6fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90009e6fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4193 1 lock held by dhcpcd/4749: #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632 2 locks held by getty/4832: #0: ffff88802ae6e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/5140: #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000430fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000430fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by syz.4.421/9468: #0: ffff8880633f5468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 3 locks held by syz.4.421/9469: 1 lock held by syz.3.456/9789: #0: ffff88806072b468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 3 locks held by syz.3.456/9790: 1 lock held by syz.0.471/9901: #0: ffff88807d60d468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106 1 lock held by syz.0.471/9902: 1 lock held by syz-executor/10531: #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632 1 lock held by syz-executor/10590: #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632 7 locks held by syz-executor/10614: #0: ffff88801e58e420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline] #0: ffff88801e58e420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586 #1: ffff888067880888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff8880230385a8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8eee6ec8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff888057d3b0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff888057d3b0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1093 [inline] #4: ffff888057d3b0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1290 #5: ffff888065796250 (&devlink->lock_key#54){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 1 lock held by syz-executor/10646: #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5d9948 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-01155-gd67978318827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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+0xfde/0x1020 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 PID: 9902 Comm: syz.0.471 Not tainted 6.10.0-syzkaller-01155-gd67978318827 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0x10c/0x780 kernel/locking/lockdep.c:4340 Code: 40 4c 89 f3 48 c1 eb 03 80 3c 13 00 74 12 4c 89 f7 e8 48 8a 86 00 48 ba 00 00 00 00 00 fc ff df 48 c7 44 24 40 00 00 00 00 9c <8f> 44 24 40 80 3c 13 00 74 12 4c 89 f7 e8 32 89 86 00 48 ba 00 00 RSP: 0018:ffffc9000490f958 EFLAGS: 00000046 RAX: 0000000000000004 RBX: 1ffff92000921f34 RCX: ffffffff94774703 RDX: dffffc0000000000 RSI: ffffffff8c1f54c0 RDI: ffffffff8c1f5480 RBP: ffffc9000490fa10 R08: ffffffff8fac7fef R09: 1ffffffff1f58ffd R10: dffffc0000000000 R11: fffffbfff1f58ffe R12: ffff8880647ada00 R13: 0000000000000000 R14: ffffc9000490f9a0 R15: 1ffff92000921f30 FS: 00007f1aca02e6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020008040 CR3: 0000000057a64000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61 do_user_addr_fault arch/x86/mm/fault.c:1283 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x113/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_nocheck_4+0x7/0x20 arch/x86/lib/putuser.S:97 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc9000490fb38 EFLAGS: 00050246 RAX: 0000000000000008 RBX: ffff88802e09812c RCX: 0000000020008040 RDX: ffff8880647ada00 RSI: 0000000000000008 RDI: 0000000000000000 RBP: ffffc9000490fdb8 R08: ffffffff82203b66 R09: 1ffff11003e6e8fb R10: dffffc0000000000 R11: ffffed1003e6e8fc R12: 0000000020008040 R13: 0000000000000000 R14: 0000000000000008 R15: 1ffff11005c13025 epoll_put_uevent include/linux/eventpoll.h:81 [inline] ep_send_events fs/eventpoll.c:1876 [inline] ep_poll fs/eventpoll.c:2005 [inline] do_epoll_wait+0xe3a/0x2040 fs/eventpoll.c:2464 do_epoll_pwait+0x56/0x1e0 fs/eventpoll.c:2498 __do_sys_epoll_pwait fs/eventpoll.c:2511 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2505 [inline] __x64_sys_epoll_pwait+0x2b8/0x310 fs/eventpoll.c:2505 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1ac9175bd9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1aca02e048 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 00007f1ac9303f60 RCX: 00007f1ac9175bd9 RDX: 0000000000000001 RSI: 0000000020008040 RDI: 0000000000000008 RBP: 00007f1ac91e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000401 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f1ac9303f60 R15: 00007ffd9dbf9788