INFO: task syz.1.543:7589 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.543 state:D stack:25448 pid:7589 ppid:4264 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
iterate_supers+0xa4/0x1d0 fs/super.c:755
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7eff8ad8f749
RSP: 002b:00007eff8bcd9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007eff8afe5fa0 RCX: 00007eff8ad8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007eff8afe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007eff8afe6038 R14: 00007eff8afe5fa0 R15: 00007ffc43e12c18
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by udevd/3636:
2 locks held by getty/4026:
#0: ffff88814e060098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by udevd/4255:
2 locks held by kworker/u4:5/4338:
5 locks held by kworker/u4:12/4616:
1 lock held by syz.3.504/7318:
#0: ffff88805e9da0e0 (&type->s_umount_key#51/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228
1 lock held by syz.1.543/7589:
#0: ffff88805e9da0e0 (&type->s_umount_key#56){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
1 lock held by syz-executor/8755:
1 lock held by syz.3.831/9665:
#0: ffff88805e9da0e0 (&type->s_umount_key#56){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
5 locks held by syz-executor/10016:
#0: ffff88807e16c460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
#1: ffff888078fc3088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff888144f1cbd0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888144f1cbd0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209
#4: ffff8880267070e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#4: ffff8880267070e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline]
#4: ffff8880267070e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283
2 locks held by syz.0.887/10068:
5 locks held by syz.0.887/10108:
3 locks held by syz.9.889/10084:
2 locks held by sed/10112:
1 lock held by syz.8.893/10116:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10110 Comm: syz.0.887 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:_copy_from_user+0x101/0x170 lib/usercopy.c:26
Code: b4 79 fd 0f ae e8 4c 89 f7 89 de e8 79 e7 c9 fd 4c 89 fe 4c 89 f7 89 da e8 6c ef fc 05 41 89 c7 31 ff 4c 89 fe e8 4f b8 79 fd <4d> 85 ff 75 11 e8 65 b4 79 fd 4c 89 f8 5b 41 5c 41 5e 41 5f 5d c3
RSP: 0018:ffffc9000c987cd0 EFLAGS: 00000297
RAX: ffffffff84072b61 RBX: 00000000000000c0 RCX: ffff88801a325940
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff52001930fc4
R10: 0000000000000000 R11: 0000000000000010 R12: 00007fffffffef40
R13: 1ffff92001930ffe R14: ffffc9000c987d60 R15: 0000000000000000
FS: 00007f60884da6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 000000004682b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
copy_from_user include/linux/uaccess.h:161 [inline]
restore_sigcontext arch/x86/kernel/signal.c:92 [inline]
__ia32_sys_rt_sigreturn+0x1e6/0x790 arch/x86/kernel/signal.c:675
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f608752b829
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007f60884d9a80 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f60877e6180 RCX: 00007f608752b829
RDX: 00007f60884d9a80 RSI: 00007f60884d9bb0 RDI: 0000000000000021
RBP: 00007f6087613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f60877e6218 R14: 00007f60877e6180 R15: 00007ffcb0bcdf48