INFO: task syz-executor:15684 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24424 pid:15684 tgid:15684 ppid:1 task_flags:0x480140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
__debugfs_file_removed fs/debugfs/inode.c:751 [inline]
remove_one+0x312/0x420 fs/debugfs/inode.c:758
__simple_recursive_removal+0x148/0x5c0 fs/libfs.c:624
debugfs_remove+0x5d/0x80 fs/debugfs/inode.c:781
nsim_dev_debugfs_exit drivers/net/netdevsim/dev.c:372 [inline]
nsim_drv_remove+0xd2/0x1e0 drivers/net/netdevsim/dev.c:1803
device_remove+0xcb/0x180 drivers/base/dd.c:619
__device_release_driver drivers/base/dd.c:1352 [inline]
device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1375
bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657
device_del+0x376/0x9b0 drivers/base/core.c:3895
device_unregister+0x1d/0xe0 drivers/base/core.c:3936
nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline]
del_device_store+0x346/0x480 drivers/net/netdevsim/bus.c:244
bus_attr_store+0x74/0xb0 drivers/base/bus.c:172
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1070 fs/read_write.c:688
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc410d5d60e
RSP: 002b:00007ffc81361ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555863f2500 RCX: 00007fc410d5d60e
RDX: 0000000000000001 RSI: 00007ffc81361f80 RDI: 0000000000000005
RBP: 00007fc410e335ec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc81361f80 R14: 00007fc411b44620 R15: 0000000000000003
INFO: task syz.4.2381:15859 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2381 state:D stack:23872 pid:15859 tgid:15858 ppid:15335 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
nsim_bus_dev_max_vfs_write+0x206/0x410 drivers/net/netdevsim/dev.c:276
full_proxy_write+0x135/0x1a0 fs/debugfs/file.c:388
vfs_write+0x2aa/0x1070 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f045fb9cdd9
RSP: 002b:00007f0460aeb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f045fe15fa0 RCX: 00007f045fb9cdd9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f045fc32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f045fe16038 R14: 00007f045fe15fa0 R15: 00007ffebf6144a8
Showing all locks held in the system:
3 locks held by kworker/1:0/24:
1 lock held by khungtaskd/30:
#0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e52e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:3/5619:
1 lock held by syz.0.33/5917:
2 locks held by getty/7173:
#0: ffff8880375970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90005e432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
1 lock held by syz.0.1806/13377:
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: acct_get kernel/acct.c:176 [inline]
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: slow_acct_process kernel/acct.c:600 [inline]
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: acct_process+0x223/0x6f0 kernel/acct.c:626
1 lock held by syz.0.1884/13701:
1 lock held by syz.0.2186/14949:
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: acct_get kernel/acct.c:176 [inline]
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: slow_acct_process kernel/acct.c:600 [inline]
#0: ffff88806b8b70f8 (&acct->lock#3){+.+.}-{4:4}, at: acct_process+0x223/0x6f0 kernel/acct.c:626
7 locks held by syz-executor/15684:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff888033fe3880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
#4: ffff888076444128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff888076444128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff888076444128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372
#5: ffff888076443258 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1e0 drivers/net/netdevsim/dev.c:1799
#6: ffff888075ad2328 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#6: ffff888075ad2328 (&sb->s_type->i_mutex_key#9/2){+.+.}-{4:4}, at: __simple_recursive_removal+0xe0/0x5c0 fs/libfs.c:620
3 locks held by syz.4.2381/15859:
#0: ffff8880269fa0f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1261
#1: ffff88801febe410 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#2: ffff888076443258 (&devlink->lock_key#4){+.+.}-{4:4}, at: nsim_bus_dev_max_vfs_write+0x206/0x410 drivers/net/netdevsim/dev.c:276
4 locks held by syz-executor/16132:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff88807925f880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/16544:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff888034b2e480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/16946:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff88805b562c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/17307:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff88805b1acc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/17653:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff888071e15c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
2 locks held by syz.2.2784/17678:
#0: ffff88801febe410 (sb_writers#8){.+.+}-{0:0}, at: open_last_lookups fs/namei.c:4600 [inline]
#0: ffff88801febe410 (sb_writers#8){.+.+}-{0:0}, at: path_openat+0x9b1/0x31a0 fs/namei.c:4855
#1: ffff888075ad2328 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
#1: ffff888075ad2328 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: open_last_lookups fs/namei.c:4610 [inline]
#1: ffff888075ad2328 (&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: path_openat+0xa16/0x31a0 fs/namei.c:4855
4 locks held by syz-executor/17739:
#0: ffff8880349c0410 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:740
#1: ffff88806ad33c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:343
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802ac3c5a8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:344
#3: ffffffff8fb80220 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 13377 Comm: syz.0.1806 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__add_to_free_list mm/page_alloc.c:792 [inline]
RIP: 0010:__free_one_page+0xb54/0x1090 mm/page_alloc.c:1015
Code: 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d5 03 00 00 8b 43 34 85 c0 0f 85 70 02 00 00 4d 85 e4 0f 95 44 24 37 <89> eb 83 fd 0b 0f 86 ec f8 ff ff 48 89 de 48 c7 c7 00 fc 9a 8e e8
RSP: 0018:ffffc90004b2f7b8 EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffffea0001852c00 RCX: 0000000000000002
RDX: 1ffffd400030a5a6 RSI: dffffc0000000000 RDI: ffffea0001852d30
RBP: 0000000000000001 R08: 1ffffd4000302d7a R09: fffff9400030a586
R10: ffffea0001852c37 R11: dffffc0000000000 R12: ffffea0001852d00
R13: dffffc0000000000 R14: ffffea0001852c00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124477000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff67217fec CR3: 00000000213c6000 CR4: 00000000003526f0
Call Trace:
free_pcppages_bulk+0x2f2/0x6c0 mm/page_alloc.c:1500
free_frozen_page_commit+0x90d/0x12b0 mm/page_alloc.c:2881
__free_frozen_pages+0x584/0x1040 mm/page_alloc.c:2970
vfree mm/vmalloc.c:3472 [inline]
vfree+0x15f/0x8d0 mm/vmalloc.c:3436
kcov_put kernel/kcov.c:442 [inline]
kcov_put kernel/kcov.c:438 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:543
__fput+0x3ff/0xb50 fs/file_table.c:510
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a60 kernel/exit.c:975
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8b/0x4f0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x6f2/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd9ed5d60e
Code: Unable to access opcode bytes at 0x7fbd9ed5d5e4.
RSP: 002b:00007fbd9cff5f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fbd9cff66c0 RCX: 00007fbd9ed5d60e
RDX: 00007fbd9cff5fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbd9ee32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd9f016038 R14: 00007fbd9f015fa0 R15: 00007ffd13e27508