INFO: task kworker/u4:3:1236 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3 state:D stack:20992 pid: 1236 ppid: 2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
rq_qos_wait+0x21d/0x330 block/blk-rq-qos.c:288
__wbt_wait block/blk-wbt.c:522 [inline]
wbt_wait+0x39e/0x680 block/blk-wbt.c:586
__rq_qos_throttle+0x61/0xa0 block/blk-rq-qos.c:72
rq_qos_throttle block/blk-rq-qos.h:203 [inline]
blk_mq_submit_bio+0x434/0x1950 block/blk-mq.c:2233
__submit_bio+0x73e/0x780 block/blk-core.c:917
__submit_bio_noacct_mq block/blk-core.c:997 [inline]
submit_bio_noacct+0x735/0x800 block/blk-core.c:1027
submit_bio+0x2c6/0x550 block/blk-core.c:1089
ext4_io_submit+0x14a/0x200 fs/ext4/page-io.c:381
ext4_writepages+0xf2f/0x2d40 fs/ext4/inode.c:2851
do_writepages+0x493/0x700 mm/page-writeback.c:2386
__writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011
wb_writeback+0x45e/0xbc0 fs/fs-writeback.c:2116
wb_check_old_data_flush fs/fs-writeback.c:2216 [inline]
wb_do_writeback fs/fs-writeback.c:2269 [inline]
wb_workfn+0xb15/0xf20 fs/fs-writeback.c:2298
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
INFO: task syz.0.247:4543 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.247 state:D stack:27696 pid: 4543 ppid: 4298 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit kernel/sched/wait_bit.c:49 [inline]
out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116
jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251
__ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235
ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866
__ext4_mark_inode_dirty+0x136/0x6c0 fs/ext4/inode.c:6040
ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6077
__mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480
generic_update_time+0x1cd/0x1f0 fs/inode.c:1881
inode_update_time fs/inode.c:1894 [inline]
file_update_time+0x3c0/0x440 fs/inode.c:2083
ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6195
do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922
do_shared_fault mm/memory.c:4328 [inline]
do_fault mm/memory.c:4396 [inline]
handle_pte_fault mm/memory.c:4650 [inline]
__handle_mm_fault mm/memory.c:4785 [inline]
handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883
do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355
handle_page_fault arch/x86/mm/fault.c:1443 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fc3a2983a23
RSP: 002b:00007ffc8fbd9be0 EFLAGS: 00010246
RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000001b31524000 RSI: 0000000000040000 RDI: 00007fc3a2cf8708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc8fbd9e70
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:2/154:
#0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
#1: ffff8880b9127888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4c3/0x810 kernel/sched/psi.c:882
4 locks held by kworker/u4:3/1236:
#0: ffff8880197e0138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900050a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff88807f0ca0e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
#3: ffff88807f0ccc58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
2 locks held by getty/3942:
#0: ffff88814d418098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:4/4250:
#0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90002fdfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by syz.0.247/4543:
#0: ffff88807c660f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807c660f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
#1: ffff88807f0ca558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline]
#1: ffff88807f0ca558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1910 [inline]
#1: ffff88807f0ca558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194
#2: ffff88807f0ce990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz-executor/4547:
#0: ffff88807f0ca460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
#1: ffff888074a5abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
#1: ffff888074a5abd0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3843
#2: ffff88807f0ce990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
2 locks held by dhcpcd/4571:
#0: ffff888075fd6120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
#0: ffff888075fd6120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3218
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:205
Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 70 13 12 0c 48 89 de 5b e9 47 5a 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 04 73 89 7e 65 8b 15 05 73 89 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900020078b0 EFLAGS: 00000246
RAX: ffffffff8954eb7f RBX: 000000000000000b RCX: ffff888017f8bb80
RDX: 0000000000000000 RSI: 0000000000000037 RDI: 000000000000021c
RBP: 000000000000021c R08: ffffffff8d8b0def R09: 1ffffffff1b161bd
R10: dffffc0000000000 R11: fffffbfff1b161be R12: 000000000000000b
R13: 0000000000000037 R14: dffffc0000000000 R15: ffff88807e15b3b0
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005636a8df9168 CR3: 000000002a90f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ieee80211_sta_get_rates+0x51f/0x6c0 net/mac80211/util.c:2128
ieee80211_update_sta_info net/mac80211/ibss.c:1007 [inline]
ieee80211_rx_bss_info net/mac80211/ibss.c:1121 [inline]
ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
ieee80211_ibss_rx_queued_mgmt+0xf79/0x2b50 net/mac80211/ibss.c:1643
ieee80211_iface_process_skb net/mac80211/iface.c:1459 [inline]
ieee80211_iface_work+0x714/0xc50 net/mac80211/iface.c:1513
cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287