INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:22832 pid:    9 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 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_lock+0xb7/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
 lock_buffer include/linux/buffer_head.h:402 [inline]
 do_get_write_access+0x1c4/0xe40 fs/jbd2/transaction.c:992
 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_mb_mark_diskspace_used+0x1c9/0x14e0 fs/ext4/mballoc.c:3871
 ext4_mb_new_blocks+0x11ab/0x47c0 fs/ext4/mballoc.c:5806
 ext4_ext_map_blocks+0x17d1/0x63d0 fs/ext4/extents.c:4372
 ext4_map_blocks+0x97f/0x1a50 fs/ext4/inode.c:675
 mpage_map_one_extent fs/ext4/inode.c:2410 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2463 [inline]
 ext4_writepages+0x124a/0x2d40 fs/ext4/inode.c:2831
 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
 </TASK>
INFO: task syz-executor:4315 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21616 pid: 4315 ppid:  4308 flags:0x00004000
Call Trace:
 <TASK>
 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_buffer include/linux/buffer_head.h:390 [inline]
 __ext4_find_entry+0x1306/0x1d20 fs/ext4/namei.c:1683
 ext4_lookup_entry fs/ext4/namei.c:1776 [inline]
 ext4_lookup+0x382/0x930 fs/ext4/namei.c:1844
 lookup_one_qstr_excl+0x10e/0x240 fs/namei.c:1571
 filename_create+0x242/0x450 fs/namei.c:3887
 do_mkdirat+0xa5/0x5c0 fs/namei.c:4131
 __do_sys_mkdirat fs/namei.c:4156 [inline]
 __se_sys_mkdirat fs/namei.c:4154 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4154
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f02526f5fc7
RSP: 002b:00007fff83607fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f025278daaf RCX: 00007f02526f5fc7
RDX: 00000000000001ff RSI: 00007f025278daaf RDI: 00000000ffffff9c
RBP: 00007fff83608050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff83608058
R13: 0000000000000002 R14: 00007fff83608238 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:4318 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22160 pid: 4318 ppid:  4311 flags:0x00004000
Call Trace:
 <TASK>
 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_buffer include/linux/buffer_head.h:390 [inline]
 __ext4_find_entry+0x1306/0x1d20 fs/ext4/namei.c:1683
 ext4_lookup_entry fs/ext4/namei.c:1776 [inline]
 ext4_lookup+0x382/0x930 fs/ext4/namei.c:1844
 lookup_one_qstr_excl+0x10e/0x240 fs/namei.c:1571
 filename_create+0x242/0x450 fs/namei.c:3887
 do_mkdirat+0xa5/0x5c0 fs/namei.c:4131
 __do_sys_mkdirat fs/namei.c:4156 [inline]
 __se_sys_mkdirat fs/namei.c:4154 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4154
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f33862bdfc7
RSP: 002b:00007ffc3cf584d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f3386355aaf RCX: 00007f33862bdfc7
RDX: 00000000000001ff RSI: 00007f3386355aaf RDI: 00000000ffffff9c
RBP: 00007ffc3cf58560 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc3cf58568
R13: 0000000000000002 R14: 00007ffc3cf58748 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
6 locks held by kworker/u4:0/9:
 #0: ffff888019f98138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88807f03e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
 #3: ffff88807f040c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
 #4: ffff88807f042990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
 #5: ffff888074b64840 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668
1 lock held by khungtaskd/27:
 #0: ffffffff8c31efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:2/154:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
 #1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4c3/0x810 kernel/sched/psi.c:882
2 locks held by getty/3944:
 #0: ffff88802c814098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by syz-executor/4223:
 #0: ffff888025a14e28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117
 #1: ffff88807f03e558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f03e558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f03e558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
2 locks held by syz-executor/4315:
 #0: ffff88807f03e460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88806dac5da8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline]
 #1: ffff88806dac5da8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3886
2 locks held by syz-executor/4318:
 #0: ffff88807f03e460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88806dac67a0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline]
 #1: ffff88806dac67a0 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3886

=============================================

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 09/16/2026
Call Trace:
 <TASK>
 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
 </TASK>
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 09/16/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:memset_erms+0xe/0x10 arch/x86/lib/memset_64.S:66
Code: b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa 4c 89 c8 <c3> 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af
RSP: 0018:ffffc90001fc7308 EFLAGS: 00000202
RAX: ffffc90001fc73f8 RBX: ffffc90001fc73a8 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90001fc7408
RBP: dffffc0000000000 R08: ffffc90001fc7407 R09: ffffc90001fc73f8
R10: dffffc0000000000 R11: fffff520003f8e81 R12: 1ffffffff1c1fa7c
R13: 1ffffffff1c1fa7c R14: ffffc90001fc73dd R15: ffffffff8e0fd3e4
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f26dbcb3000 CR3: 000000007df8d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unwind_next_frame+0x9e3/0x1cf0 arch/x86/kernel/unwind_orc.c:547
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 ieee80211_bss_info_update+0x842/0xa80 net/mac80211/scan.c:232
 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1763/0x2b50 net/mac80211/ibss.c:1643
 ieee80211_iface_process_skb net/mac80211/iface.c:1467 [inline]
 ieee80211_iface_work+0x714/0xc50 net/mac80211/iface.c:1521
 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
 </TASK>