INFO: task jbd2/sda1-8:5105 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8     state:D stack:26024 pid:5105  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_buffer include/linux/buffer_head.h:373 [inline]
 jbd2_journal_commit_transaction+0x2e8d/0x5ad0 fs/jbd2/commit.c:815
 kjournald2+0x40f/0x810 fs/jbd2/journal.c:201
 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
 </TASK>
INFO: task syz-executor:5760 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:22008 pid:5760  ppid:5759   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
 __ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
 __mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2522
 generic_update_time fs/inode.c:1981 [inline]
 inode_update_time fs/inode.c:1994 [inline]
 __file_update_time fs/inode.c:2180 [inline]
 file_update_time+0x187/0x1a0 fs/inode.c:2210
 ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
 do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
 wp_page_shared mm/memory.c:3311 [inline]
 do_wp_page+0xd4d/0x34d0 mm/memory.c:3396
 handle_pte_fault mm/memory.c:5063 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x1306/0x4a50 mm/memory.c:5353
 do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
 handle_page_fault arch/x86/mm/fault.c:1463 [inline]
 exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f37e1c7c6e2
RSP: 002b:00007fff18a84b20 EFLAGS: 00010202
RAX: 00007f37dfa20000 RBX: 00005555666636a0 RCX: 0000000000000003
RDX: 00000000000027ac RSI: 00005555666d6c80 RDI: 0000000000000008
RBP: 00007fff18a85020 R08: 00005555666d6cb8 R09: 0000000000000092
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff18a84e60
R13: 00007fff18a84c50 R14: 585858582e7a7973 R15: 00007fff18a84ba0
 </TASK>
INFO: task syz-executor:14133 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:21800 pid:14133 ppid:14124  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 __ext4_new_inode+0x140c/0x3aa0 fs/ext4/ialloc.c:1101
 ext4_mkdir+0x40b/0xc90 fs/ext4/namei.c:3068
 vfs_mkdir+0x2a5/0x470 fs/namei.c:4168
 do_mkdirat+0x1dc/0x450 fs/namei.c:4191
 __do_sys_mkdirat fs/namei.c:4206 [inline]
 __se_sys_mkdirat fs/namei.c:4204 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4204
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3e5179cfc7
RSP: 002b:00007ffc57a66b98 EFLAGS: 00000206 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f3e51834aaf RCX: 00007f3e5179cfc7
RDX: 00000000000001ff RSI: 00007f3e51834aaf RDI: 00000000ffffff9c
RBP: 00007f3e51a267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc57a66e08 R15: 0000000000000000
 </TASK>
INFO: task syz.0.3256:14231 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3256      state:D stack:27048 pid:14231 ppid:5779   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
 __wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
 jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
 __ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
 ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
 __ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
 __mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2522
 generic_update_time fs/inode.c:1981 [inline]
 inode_update_time fs/inode.c:1994 [inline]
 __file_update_time fs/inode.c:2180 [inline]
 file_update_time+0x187/0x1a0 fs/inode.c:2210
 ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
 do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
 do_shared_fault mm/memory.c:4717 [inline]
 do_fault mm/memory.c:4779 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x1a2c/0x4a50 mm/memory.c:5353
 do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
 handle_page_fault arch/x86/mm/fault.c:1463 [inline]
 exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f62ee6727a9
RSP: 002b:00007ffed88d8e30 EFLAGS: 00010202
RAX: 0000001b2d923000 RBX: ffffffff813bd28a RCX: 0000001b2d922ff8
RDX: 0000001b2d324220 RSI: 0000000000000008 RDI: 00007f62ef555720
RBP: 000000000000002d R08: 00007f62eea10000 R09: 00007f62eea12000
R10: 00000000813bd28e R11: 0000000000000003 R12: 00007f62eea26038
R13: 000000000000002c R14: ffffffff813bd108 R15: 00007f62ef555720
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6635
2 locks held by kworker/u4:9/3468:
 #0: ffff8880b8e3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6696
2 locks held by getty/5525:
 #0: ffff88802d0340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032832f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5760:
 #0: ffff88807df581a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88807df581a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88807df581a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814dee0990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
2 locks held by kworker/1:4/5831:
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900048b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900048b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
1 lock held by udevd/6128:
 #0: ffff888021cdd4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
3 locks held by syz-executor/14133:
 #0: ffff88814ded4418 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff888076d32210 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff888076d32210 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x20f/0x450 fs/namei.c:3937
 #2: ffff88814dee0990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.0.3256/14231:
 #0: ffff88801b7ea7a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88801b7ea7a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88801b7ea7a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814ded4510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814dee0990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
2 locks held by dhcpcd/14386:
 #0: ffff888078b32020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff888078b32020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff888078b32020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1421
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 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 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf59/0xfa0 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 42 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 nsim_dev_trap_report_work
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x82/0x90 kernel/kcov.c:311
Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24
RSP: 0018:ffffc90000b2f5b0 EFLAGS: 00000293
RAX: ffffffff813bc2a9 RBX: ffffc90000b28000 RCX: 0000000000000000
RDX: ffff888018ae1e00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff888018ae1e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: 1ffff92000165ed3
R13: ffffc90000b2f688 R14: ffffc90000b2fa20 R15: ffffc90000b30000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005595aad23660 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
 stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
 deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
 unwind_next_frame+0xed9/0x2990 arch/x86/kernel/unwind_orc.c:585
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x253/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 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
 </TASK>
vkms_vblank_simulate: vblank timer overrun