INFO: task syz.4.76:6346 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.76 state:D stack:24728 pid:6346 tgid:6345 ppid:5804 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 io_schedule+0x80/0xe0 kernel/sched/core.c:7831 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1170 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753 dtSplitPage+0x791/0x37c0 fs/jfs/jfs_dtree.c:1471 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x10a4/0x5f10 fs/jfs/jfs_dtree.c:871 jfs_create+0x75b/0xb10 fs/jfs/namei.c:138 lookup_open fs/namei.c:4483 [inline] open_last_lookups fs/namei.c:4583 [inline] path_openat+0x13b4/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f448a7abf79 RSP: 002b:00007f44889fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f448aa25fa0 RCX: 00007f448a7abf79 RDX: 0000000000048042 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f448a8427e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f448aa26038 R14: 00007f448aa25fa0 R15: 00007fff66598898 INFO: task syz.4.76:6364 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.76 state:D stack:25912 pid:6364 tgid:6345 ppid:5804 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4580 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f448a7abf79 RSP: 002b:00007f44889dd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f448aa26090 RCX: 00007f448a7abf79 RDX: 000000000000275a RSI: 0000200000000600 RDI: ffffffffffffff9c RBP: 00007f448a8427e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f448aa26128 R14: 00007f448aa26090 R15: 00007fff66598898 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/42: 4 locks held by kworker/u8:6/1288: #0: ffff88801f6f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801f6f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc900050d7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900050d7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffff88803c9420d0 (&type->s_umount_key#79){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88805d92e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 3 locks held by kworker/u8:9/1399: #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90005427c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005427c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 4 locks held by kworker/u8:11/1417: #0: ffff88801f6f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801f6f0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc900056f7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900056f7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffff88802433c0d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88805e131a80 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2313 [inline] #3: ffff88805e131a80 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x3fc/0x690 fs/f2fs/checkpoint.c:1893 1 lock held by dhcpcd/5465: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x23d/0x370 net/ipv6/addrconf.c:4799 2 locks held by getty/5562: #0: ffff888027c380a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5806: 3 locks held by syz.3.19/6020: 4 locks held by syz.4.76/6346: #0: ffff88803c942480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 #2: ffff88805d92e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x22e/0xb10 fs/jfs/namei.c:101 #3: ffff8880603b4fe8 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x249/0xb10 fs/jfs/namei.c:102 2 locks held by syz.4.76/6364: #0: ffff88803c942480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff88805d92e738 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 1 lock held by syz-executor/6472: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436 7 locks held by syz-executor/7354: #0: ffff88803695e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88803695e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88805aabbc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880277f94b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880277f94b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e7bc838 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff88802fc870d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88802fc870d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #5: ffff888039ddc300 (&devlink->lock_key#12){+.+.}-{4:4}, at: nsim_drv_probe+0xc9/0xc30 drivers/net/netdevsim/dev.c:1637 #6: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1049 [inline] #6: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x839/0x1120 drivers/net/netdevsim/netdev.c:1143 4 locks held by syz-executor/7404: #0: ffff88803695e480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff88803695e480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88806565c078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880277f93c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880277f93c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e7bc838 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 2 locks held by syz-executor/7465: #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz-executor/7572: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bf/0x1e10 drivers/net/tun.c:3078 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: 6020 Comm: syz.3.19 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x92/0xa0 kernel/kcov.c:323 Code: c1 e1 05 4c 8d 51 28 4d 39 ca 77 1e 49 ff c0 4c 89 02 48 c7 44 0a 08 07 00 00 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 cc cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90005607430 EFLAGS: 00000297 RAX: ffffffff8424550c RBX: ffffea000186f940 RCX: ffff88801db81e00 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff9400030df29 R12: 0000000000000001 R13: dffffc0000000000 R14: ffffea0000e4bec8 R15: dffffc0000000000 FS: 00007f04c6a266c0(0000) GS:ffff888126695000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055cbd717aa38 CR3: 0000000024d46000 CR4: 00000000003526f0 Call Trace: const_folio_flags include/linux/page-flags.h:351 [inline] folio_test_locked include/linux/page-flags.h:551 [inline] f2fs_folio_put+0x6c/0x1a0 fs/f2fs/f2fs.h:2989 __get_node_folio+0x11aa/0x1800 fs/f2fs/node.c:1590 f2fs_update_inode_page+0x83/0x2e0 fs/f2fs/inode.c:772 f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1156 [inline] block_operations fs/f2fs/checkpoint.c:1263 [inline] f2fs_write_checkpoint+0xbd5/0x2490 fs/f2fs/checkpoint.c:1678 f2fs_issue_checkpoint+0x40c/0x690 fs/f2fs/checkpoint.c:1894 f2fs_do_sync_file+0x81b/0x19d0 fs/f2fs/file.c:354 vfs_fsync_range fs/sync.c:188 [inline] vfs_fsync fs/sync.c:202 [inline] do_fsync fs/sync.c:213 [inline] __do_sys_fsync fs/sync.c:218 [inline] __se_sys_fsync fs/sync.c:216 [inline] __x64_sys_fsync+0x130/0x190 fs/sync.c:216 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04c87cbf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f04c6a26028 EFLAGS: 00000246 ORIG_RAX: 000000000000004a RAX: ffffffffffffffda RBX: 00007f04c8a45fa0 RCX: 00007f04c87cbf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f04c88627e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f04c8a46038 R14: 00007f04c8a45fa0 R15: 00007fffdb245d58