INFO: task syz.4.103:6677 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.103 state:D stack:25952 pid:6677 tgid:6652 ppid:5802 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 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 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1043 [inline] lookup_slow+0x46/0x70 fs/namei.c:1932 walk_component fs/namei.c:2279 [inline] lookup_last fs/namei.c:2780 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2804 filename_lookup+0x256/0x5d0 fs/namei.c:2833 vfs_statx+0xfc/0x200 fs/stat.c:353 vfs_fstatat fs/stat.c:373 [inline] vfs_stat include/linux/fs.h:3196 [inline] __do_sys_newstat fs/stat.c:511 [inline] __se_sys_newstat fs/stat.c:505 [inline] __x64_sys_newstat+0x125/0x1e0 fs/stat.c:505 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: 0033:0x7f70c11cc799 RSP: 002b:00007f70bf3fd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 00007f70c1446090 RCX: 00007f70c11cc799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000180 RBP: 00007f70c1262c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f70c1446128 R14: 00007f70c1446090 R15: 00007fff60d647a8 INFO: task syz.4.103:6682 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.103 state:D stack:25384 pid:6682 tgid:6652 ppid:5802 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 io_schedule+0x80/0xe0 kernel/sched/core.c:7835 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: 0033:0x7f70c11cc799 RSP: 002b:00007f70befb9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f70c1446270 RCX: 00007f70c11cc799 RDX: 000000000000275a RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f70c1262c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f70c1446308 R14: 00007f70c1446270 R15: 00007fff60d647a8 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:1/48: 3 locks held by kworker/u8:6/119: 4 locks held by kworker/u8:7/773: #0: ffff88801f6e7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f6e7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90004a2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90004a2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888035a8a0d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888050056368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 5 locks held by kworker/u8:11/1435: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90006277c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90006277c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14c400 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffff888061d920d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888061d920d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff888061d920d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:504 #4: ffff888065596300 (&devlink->lock_key#6){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:274 [inline] #4: ffff888065596300 (&devlink->lock_key#6){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888065596300 (&devlink->lock_key#6){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:504 3 locks held by kworker/u8:12/1446: #0: ffff888031b9c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888031b9c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90006247c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90006247c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 1 lock held by udevd/5167: 2 locks held by getty/5561: #0: ffff88803753f0a0 (&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.4.103/6677: #0: ffff888050056738 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888050056738 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932 4 locks held by syz.4.103/6682: #0: ffff888035a8a480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888050056738 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888050056738 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff888050056738 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 #2: ffff888050056368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x22e/0xb10 fs/jfs/namei.c:101 #3: ffff8880619a01e8 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x249/0xb10 fs/jfs/namei.c:102 2 locks held by syz.9.257/7888: #0: ffff888035a8a0d0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888035a8a0d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff888025c9e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff888025c9e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922 2 locks held by syz.9.257/7891: #0: ffff888035a8a0d0 (&type->s_umount_key#62){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888035a8a0d0 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff888025c9e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff888025c9e8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922 3 locks held by syz-executor/8171: 1 lock held by syz-executor/8591: #0: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5031 1 lock held by syz-executor/8736: 5 locks held by syz.8.369/8943: 2 locks held by syz.3.374/8986: ============================================= NMI backtrace for cpu 1 CPU: 1 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5167 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__lock_acquire+0x26a/0x2cf0 kernel/locking/lockdep.c:-1 Code: 74 24 18 48 89 ee 4d 89 ce e8 b2 37 3a 03 4d 89 f1 48 8b 74 24 18 44 8b 74 24 20 48 83 bc 24 20 01 00 00 00 0f 85 ce fe ff ff <44> 89 74 24 20 44 89 3c 24 8b bc 24 38 01 00 00 4c 8b 84 24 28 01 RSP: 0018:ffffc9000495f5d0 EFLAGS: 00000046 RAX: 0000000000000113 RBX: 0000000000000000 RCX: ffffffff92f703f0 RDX: 0000000000000000 RSI: 000000000000000b RDI: ffffffff8ddcb980 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ddcb980 R10: 0000000000000000 R11: ffffed1008a7431a R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f7af5c49880(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555696cdaa8 CR3: 00000000397c8000 CR4: 00000000003526f0 Call Trace: reacquire_held_locks+0x104/0x190 kernel/locking/lockdep.c:5385 __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x199/0x3d0 kernel/locking/lockdep.c:5889 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline] __skb_try_recv_datagram net/core/datagram.c:267 [inline] __skb_recv_datagram+0x11d/0x2d0 net/core/datagram.c:297 skb_recv_datagram+0x47/0x70 net/core/datagram.c:317 netlink_recvmsg+0x10f/0xa50 net/netlink/af_netlink.c:1916 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x172/0x1b0 net/socket.c:1100 ____sys_recvmsg+0x1f2/0x4b0 net/socket.c:2812 ___sys_recvmsg+0x215/0x590 net/socket.c:2854 __sys_recvmsg net/socket.c:2887 [inline] __do_sys_recvmsg net/socket.c:2893 [inline] __se_sys_recvmsg net/socket.c:2890 [inline] __x64_sys_recvmsg+0x1c0/0x2a0 net/socket.c:2890 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: 0033:0x7f7af5d37407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff3018eae0 EFLAGS: 00000202 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007f7af5c49880 RCX: 00007f7af5d37407 RDX: 0000000000000000 RSI: 00007fff3018eb70 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000556433c9e9e0 R13: 00007fff3018ec30 R14: 00007fff3018eb7c R15: 0000000000000000