INFO: task kworker/u4:11:7591 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:11 state:D stack:22072 pid:7591 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:6)
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
INFO: task syz.6.920:10965 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.920 state:D stack:22536 pid:10965 ppid:7390 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
__lock_metapage fs/jfs/jfs_metapage.c:50 [inline]
lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64
__get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639
xtSplitRoot+0x104/0x1030 fs/jfs/jfs_xtree.c:1227
xtSplitUp+0x347/0x1f30 fs/jfs/jfs_xtree.c:770
xtInsert+0x3ef/0xe00 fs/jfs/jfs_xtree.c:593
extAlloc+0x9fa/0xf30 fs/jfs/jfs_extent.c:145
jfs_get_block+0x347/0xab0 fs/jfs/inode.c:254
__block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124
__block_write_begin fs/buffer.c:2173 [inline]
block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305
generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031
generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152
do_iter_readv_writev fs/read_write.c:-1 [inline]
do_iter_write+0x79a/0xc70 fs/read_write.c:860
iter_file_splice_write+0x66f/0xc50 fs/splice.c:736
do_splice_from fs/splice.c:933 [inline]
direct_splice_actor+0xe8/0x130 fs/splice.c:1142
splice_direct_to_actor+0x2f0/0x870 fs/splice.c:1088
do_splice_direct+0x1b7/0x2c0 fs/splice.c:1194
do_sendfile+0x5dc/0xf70 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64+0x13f/0x190 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3da198f749
RSP: 002b:00007f3da28f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f3da1be5fa0 RCX: 00007f3da198f749
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 00007f3da1a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000e3aa6ea R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3da1be6038 R14: 00007f3da1be5fa0 R15: 00007ffc1cb6f2d8
INFO: task syz.6.920:10972 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.920 state:D stack:22736 pid:10972 ppid:7390 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
__lock_metapage fs/jfs/jfs_metapage.c:50 [inline]
lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64
__get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639
xtSplitPage+0x26b/0x2170 fs/jfs/jfs_xtree.c:974
xtSplitUp+0x328/0x1f30 fs/jfs/jfs_xtree.c:771
xtInsert+0x3ef/0xe00 fs/jfs/jfs_xtree.c:593
extAlloc+0x9fa/0xf30 fs/jfs/jfs_extent.c:145
jfs_get_block+0x347/0xab0 fs/jfs/inode.c:254
__block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124
__block_write_begin fs/buffer.c:2173 [inline]
block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305
generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031
generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152
__kernel_write_iter+0x274/0x670 fs/read_write.c:517
dump_emit_page fs/coredump.c:957 [inline]
dump_user_range+0x3f6/0x800 fs/coredump.c:984
elf_core_dump+0x3114/0x36e0 fs/binfmt_elf.c:2184
do_coredump+0x1755/0x2480 fs/coredump.c:833
get_signal+0x1133/0x1400 kernel/signal.c:2888
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315
exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f3da198f751
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f3da1be6090 RCX: 00007f3da198f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f3da1a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f3da1be6128 R14: 00007f3da1be6090 R15: 00007ffc1cb6f2d8
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:4/59:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566
#1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
2 locks held by dhcpcd/5429:
#0: ffff88801cb34690 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0xf4/0x810 net/netlink/af_netlink.c:2336
#1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x71f/0xde0 net/netlink/af_netlink.c:2263
2 locks held by getty/5526:
#0: ffff88802d5370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
4 locks held by kworker/u4:11/7591:
#0: ffff888019e70138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888019e70138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000382fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000382fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88805e8140e0 (&type->s_umount_key#71){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff888076b5b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
3 locks held by kworker/u4:12/8102:
2 locks held by kworker/1:7/8461:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900042efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900042efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by syz-executor/10652:
6 locks held by kworker/0:10/10870:
#0: ffff888019ac8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888019ac8138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000434fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000434fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880257e4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff8880257e4190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
#3: ffff88805dbc4190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#3: ffff88805dbc4190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
#4: ffff888021057160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#4: ffff888021057160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
#5: ffffffff8cbda630 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:215
4 locks held by syz.6.920/10965:
#0: ffff88805e814418 (sb_writers#18){.+.+}-{0:0}, at: do_sendfile+0x5b9/0xf70 fs/read_write.c:1253
#1: ffff888076b5bd10 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff888076b5bd10 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149
#2: ffff888076b5b8b8 (&jfs_ip->rdwrlock#3){++++}-{3:3}, at: jfs_get_block+0x142/0xab0 fs/jfs/inode.c:219
#3: ffff888076b5b948 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10f/0xf30 fs/jfs/jfs_extent.c:81
4 locks held by syz.6.920/10972:
#0: ffff88805e814418 (sb_writers#18){.+.+}-{0:0}, at: do_coredump+0x1734/0x2480 fs/coredump.c:832
#1: ffff888076b5c650 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff888076b5c650 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4149
#2: ffff888076b5c1f8 (&jfs_ip->rdwrlock#3){++++}-{3:3}, at: jfs_get_block+0x142/0xab0 fs/jfs/inode.c:219
#3: ffff888076b5c288 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10f/0xf30 fs/jfs/jfs_extent.c:81
2 locks held by syz.0.1225/13132:
#0: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516
#1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0xc4/0x620 net/ipv6/ip6_tunnel.c:2292
1 lock held by dhcpcd/13167:
#0: ffff88805a60fa20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88805a60fa20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
#0: ffff88805a60fa20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1421
2 locks held by dhcpcd/13173:
#0: ffff88807cc62130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1767 [inline]
#0: ffff88807cc62130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 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+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1097 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:unwind_next_frame+0x1c89/0x2970 arch/x86/kernel/unwind_orc.c:665
Code: e8 0c 3f a2 00 4d 8b 74 24 38 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 42 80 3c 28 00 48 8b ac 24 90 00 00 00 74 05 e8 e7 3e a2 00 <49> 8b 5c 24 08 4d 8d 7c 24 10 4c 89 f8 48 c1 e8 03 42 80 3c 28 00
RSP: 0018:ffffc900046bf4d8 EFLAGS: 00000246
RAX: 1ffff920008d7eb6 RBX: ffffc900046bf5e0 RCX: 0000000000000000
RDX: ffff888023d43c00 RSI: 0000000000000001 RDI: ffffc900046bf5b0
RBP: ffffc900046bff30 R08: ffff888023d43c00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900046bf5a8
R13: dffffc0000000000 R14: ffffc900046bff58 R15: ffffffff8ecb6226
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc8a4a3ea4 CR3: 000000005b5f7000 CR4: 00000000003506e0
Call Trace:
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:949 [inline]
skb_free_head net/core/skbuff.c:961 [inline]
skb_release_data+0x634/0x800 net/core/skbuff.c:991
skb_release_all net/core/skbuff.c:1057 [inline]
__kfree_skb net/core/skbuff.c:1071 [inline]
consume_skb+0xb2/0x110 net/core/skbuff.c:1287
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x76f/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293