INFO: task syz.8.615:12437 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.615 state:D stack:27992 pid:12437 tgid:12383 ppid:6823 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]
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
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_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
filename_create+0x200/0x370 fs/namei.c:4922
filename_mkdirat+0xd2/0x520 fs/namei.c:5259
__do_sys_mkdirat fs/namei.c:5287 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5284
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: 0033:0x7f0a1b32b607
RSP: 002b:00007f0a11143e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0a11143ee0 RCX: 00007f0a1b32b607
RDX: 00000000000001ff RSI: 0000200000000100 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007f0a11143ea0 R14: 0000000000000000 R15: 0000000000000000
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
3 locks held by kworker/u8:5/135:
#0: ffff88803233a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88803233a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90003a3fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90003a3fc40 ((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
4 locks held by kworker/u8:9/1482:
#0: ffff88801f29e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801f29e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90006597c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90006597c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff8880354a20d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88805f1d3c68 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by kworker/u8:11/4872:
#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: ffffc90010f47c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90010f47c40 (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: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0xa00 net/core/dev.c:13055
2 locks held by dhcpcd/5457:
#0: ffffffff8f13c0f8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x644/0x7f0 net/socket.c:1337
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:579
2 locks held by getty/5551:
#0: ffff8880375970a0 (&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
9 locks held by syz-executor/6700:
1 lock held by udevd/11695:
4 locks held by syz.8.615/12435:
2 locks held by syz.8.615/12437:
#0: ffff8880354a2480 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88805f1d4038 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88805f1d4038 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff88805f1d4038 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff88805f1d4038 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
2 locks held by syz.3.756/14582:
#0: ffff8880354a20d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880354a20d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888025a348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888025a348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
2 locks held by syz.3.756/14608:
#0: ffff8880354a20d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880354a20d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888025a348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888025a348c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
1 lock held by syz-executor/14710:
#0: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
4 locks held by syz-executor/14884:
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff88801ae93c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802820c788 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802820c788 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e9c85d8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184
7 locks held by syz-executor/14923:
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff88805f53f478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802820c698 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802820c698 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e9c85d8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff8880573990d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff8880573990d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff8880573990d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1304
#5: ffff88803feb0300 (&devlink->lock_key#16){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162
4 locks held by syz-executor/15141:
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88803799a480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff888061777c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802820c698 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802820c698 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e9c85d8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
5 locks held by kworker/u8:14/16054:
=============================================
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: 5152 Comm: klogd 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+0x87e/0x2cf0 kernel/locking/lockdep.c:5232
Code: f3 c1 c3 10 31 cb 01 d6 29 da 89 dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 83 3d 09 17 ca 0d 00 4d 89 e5 <0f> 85 1f 02 00 00 48 83 7c 24 28 00 0f 84 b3 01 00 00 41 8b 45 f8
RSP: 0018:ffffc90003c5f6e8 EFLAGS: 00000046
RAX: 000000000008810d RBX: 00000000cf096ae6 RCX: 0000000008896c7d
RDX: 00000000877bc155 RSI: 00000000984dcac9 RDI: ffff888038e0db80
RBP: 6a4de25c00000000 R08: ffffffff8212444f R09: ffff888038a8b6b0
R10: dffffc0000000000 R11: ffffed1006f04b74 R12: ffff888038e0e738
R13: ffff888038e0e738 R14: ffff888038e0db80 R15: 0000000000000000
FS: 00007f56217bdc80(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37f3b956b8 CR3: 00000000388f6000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__might_fault+0xcb/0x130 mm/memory.c:7218
_copy_from_iter+0x100/0x1670 lib/iov_iter.c:271
copy_from_iter include/linux/uio.h:228 [inline]
skb_copy_datagram_from_iter+0xf5/0x710 net/core/datagram.c:561
unix_dgram_sendmsg+0x521/0x18e0 net/unix/af_unix.c:2140
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x67f/0x710 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2209
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: 0033:0x7f562190d407
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:00007ffcdfbd96f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f56217bdc80 RCX: 00007f562190d407
RDX: 0000000000000051 RSI: 00007ffcdfbd9830 RDI: 0000000000000003
RBP: 00007ffcdfbd9c60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcdfbd9c78
R13: 00007ffcdfbd9830 R14: 0000000000000036 R15: 00007ffcdfbd9830