INFO: task syz.8.315:19442 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.315 state:D stack:28280 pid:19442 tgid:19431 ppid:17943 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
filename_create+0x14f/0x360 fs/namei.c:4872
do_mkdirat+0xca/0x4b0 fs/namei.c:5156
__do_sys_mkdir fs/namei.c:5191 [inline]
__se_sys_mkdir fs/namei.c:5189 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:5189
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbcfe6cf749
RSP: 002b:00007fbcfc8ec038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fbcfe926180 RCX: 00007fbcfe6cf749
RDX: 0000000000000000 RSI: 000000000000010b RDI: 0000200000000040
RBP: 00007fbcfe753f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbcfe926218 R14: 00007fbcfe926180 R15: 00007ffea6c93858
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/68:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000153fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000153fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by udevd/5170:
2 locks held by dhcpcd/5464:
#0: ffffffff8e90dd60 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17932
2 locks held by getty/5560:
#0: ffff888034b2a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:7/5939:
#0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc900054afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc900054afbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
4 locks held by kworker/u8:22/9796:
2 locks held by syz-executor/17328:
1 lock held by syz.8.315/19442:
#0: ffff88805525a480 (sb_writers#31){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
1 lock held by syz-executor/22392:
#0: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027
4 locks held by syz-executor/22583:
#0: ffff888034e6c480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888034e6c480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff888020fe6878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888143fde4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888143fde4b8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e12c678 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
7 locks held by syz-executor/22842:
#0: ffff888034e6c480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888034e6c480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805c5a9c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888143fde5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888143fde5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e12c678 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff8880315c80d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff8880315c80d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
#4: ffff8880315c80d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302
#5: ffff8880315c9300 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1777
#6: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175
2 locks held by syz-executor/23188:
#0: ffffffff8e0f61e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e0f61e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e0f61e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5170 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__d_lookup+0x213/0x780 fs/dcache.c:2439
Code: c1 e9 03 48 89 4c 24 60 48 89 54 24 58 48 c1 ea 03 48 89 54 24 50 48 89 1c 24 48 83 c3 18 48 89 d8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 21 03 00 00 8b 1b 89 df 44 89 f6 e8 79 5c 8a ff 44 39
RSP: 0018:ffffc90004a2fa28 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff88805d45b868 RCX: 1ffff92000945f8e
RDX: 1ffff92000945f8f RSI: ffff88805d45b850 RDI: 0000000000000000
RBP: ffff88803aeedb80 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200013c3b9 R12: dffffc0000000000
R13: ffffc90004a2fc70 R14: 00000000fc3b8db8 R15: ffffffff82354da6
FS: 00007f4ba20fd880(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4ba179f000 CR3: 0000000037344000 CR4: 00000000003526f0
Call Trace:
lookup_fast+0x84/0x5b0 fs/namei.c:1816
walk_component fs/namei.c:2217 [inline]
lookup_last fs/namei.c:2722 [inline]
path_lookupat+0x209/0x8c0 fs/namei.c:2746
filename_lookup+0x212/0x570 fs/namei.c:2775
do_readlinkat+0xd9/0x500 fs/stat.c:576
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:610
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ba22593a7
Code: 00 00 90 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 00 31 c9 e8 8a 20 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 ba 0d 00 f7 d8 64 89 02 48
RSP: 002b:00007ffda3a03868 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffda3a03d40 RCX: 00007f4ba22593a7
RDX: 0000000000000400 RSI: 00007ffda3a03870 RDI: 00007ffda3a03d40
RBP: 00007ffda3a03870 R08: 0000563341efced4 R09: 0000000000000040
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 0000000000000100 R14: 000056330990cbe0 R15: 00007ffda3a047c0