INFO: task syz.0.34:5602 blocked for more than 146 seconds. Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.34 state:D stack:24848 pid:5602 tgid:5532 ppid:5229 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 fdget_pos+0x24e/0x320 fs/file.c:1187 ksys_write+0x7e/0x2b0 fs/read_write.c:727 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: 0033:0x7f5fc997dff9 RSP: 002b:00007f5fca720038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5fc9b36058 RCX: 00007f5fc997dff9 RDX: 0000000000000118 RSI: 0000000020000280 RDI: 0000000000000006 RBP: 00007f5fc99f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5fc9b36058 R15: 00007fffdb621718 Showing all locks held in the system: 3 locks held by kworker/u8:0/11: #0: ffff88802d95e948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88802d95e948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000107d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000107d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 3 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 3 locks held by kworker/u8:2/35: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 5 locks held by kworker/u8:6/2515: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900096f7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900096f7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb2450 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11930 #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 2 locks held by kworker/u8:9/2641: 2 locks held by dhcpcd/4888: #0: ffff88807d4316c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2404 #1: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6505 2 locks held by getty/4976: #0: ffff8880275ef0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz.0.34/5534: #0: ffff888028fbb438 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1187 #1: ffff8880300e4420 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #1: ffff8880300e4420 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 1 lock held by syz.0.34/5602: #0: ffff888028fbb438 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1187 2 locks held by bch-copygc/loop/5580: 1 lock held by syz.1.65/5834: #0: ffff88806773e420 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff88806773e420 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 1 lock held by bch-reclaim/loo/5850: 1 lock held by syz-executor/6471: #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/6533: #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/6534: #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 4 locks held by syz-executor/6537: #0: ffff888033736420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff888033736420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff888029151088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8881433e8a58 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f55cfc8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 7 locks held by syz-executor/6539: #0: ffff888033736420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff888033736420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88802f5c1488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8881433e8968 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f55cfc8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff8880605680e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff8880605680e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #5: ffff8880604f3250 (&devlink->lock_key#14){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534 #6: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:678 [inline] #6: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x408/0x890 drivers/net/netdevsim/netdev.c:750 1 lock held by syz-executor/6708: #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbef48 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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: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: 5850 Comm: bch-reclaim/loo Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x86/0x290 mm/kasan/generic.c:189 Code: 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 <0f> 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00 00 45 89 dc RSP: 0018:ffffc900093c74c8 EFLAGS: 00000246 RAX: ffffffff84207f01 RBX: 1ffff920039c0000 RCX: ffffffff84207fd5 RDX: 0000000000000001 RSI: 0000000000000050 RDI: ffffc9001ce00000 RBP: fffffffffffffff7 R08: ffffc9001ce0004f R09: 1ffff920039c0009 R10: dffffc0000000000 R11: fffff520039c0001 R12: 0000000000000050 R13: ffffc9001ce00000 R14: dffffc0000000001 R15: fffff520039c000a FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff4fa265000 CR3: 0000000030f7a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 bch2_btree_write_buffer_flush_locked+0x54a5/0x59f0 fs/bcachefs/btree_write_buffer.c:465 btree_write_buffer_flush_seq+0x1a43/0x1bc0 fs/bcachefs/btree_write_buffer.c:510 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565 __bch2_journal_reclaim+0x789/0xdc0 fs/bcachefs/journal_reclaim.c:698 bch2_journal_reclaim_thread+0x174/0x560 fs/bcachefs/journal_reclaim.c:740 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