INFO: task kworker/u4:10:4183 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:10   state:D stack:21784 pid:4183  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
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
 add_transaction_credits fs/jbd2/transaction.c:300 [inline]
 start_this_handle+0x103f/0x2170 fs/jbd2/transaction.c:407
 jbd2__journal_start+0x2bb/0x5b0 fs/jbd2/transaction.c:505
 __ext4_journal_start_sb+0x203/0x560 fs/ext4/ext4_jbd2.c:112
 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
 ext4_do_writepages+0xfb9/0x3990 fs/ext4/inode.c:2716
 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2822
 do_writepages+0x351/0x590 mm/page-writeback.c:2575
 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1686
 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1977
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2048
 wb_writeback+0x472/0xbe0 fs/fs-writeback.c:2158
 wb_check_background_flush fs/fs-writeback.c:2228 [inline]
 wb_do_writeback fs/fs-writeback.c:2316 [inline]
 wb_workfn+0xb8e/0xe60 fs/fs-writeback.c:2343
 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>
INFO: task syz.1.79:6028 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.79        state:D stack:25384 pid:6028  ppid:5776   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: 0033:0x7fc2fcc72809
RSP: 002b:00007fff369ce670 EFLAGS: 00010202
RAX: 0000001b2dd24000 RBX: 0000000000000000 RCX: 00000000005ffde8
RDX: 0000001b2dd23ffc RSI: 00000000005ffde8 RDI: 00007fc2fdb55700
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fc2fd012000
R10: 00007fc2fdb55700 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000035070 R14: ffffffff81321df0 R15: 00007fc2fdb55720
 </TASK>
INFO: task syz.2.82:6034 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.82        state:D stack:27048 pid:6034  ppid:5778   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: 0033:0x7fda78c72f32
RSP: 002b:00007fff1202d450 EFLAGS: 00010202
RAX: 0000000000002008 RBX: 00007fda79b55720 RCX: 0000000000000000
RDX: 0000001b2de22000 RSI: 0000000000000008 RDI: 00007fda79b55720
RBP: 000000000000064e R08: 00007fda79010000 R09: 00007fda79026038
R10: 0000000000000003 R11: 0000000000000002 R12: ffffffff88be6d57
R13: 00007fda79026038 R14: 0000000000000115 R15: ffffffffffffe000
 </TASK>
INFO: task syz.3.86:6044 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.86        state:D stack:27560 pid:6044  ppid:5775   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: 0033:0x7f8b6cc6baa3
RSP: 002b:00007ffd152dc480 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2d964000
RDX: 0000001b2d924000 RSI: 0000000000600000 RDI: 00007f8b6cfe0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd152dc710
 </TASK>
INFO: task syz.0.87:6045 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.87        state:D stack:26328 pid:6045  ppid:5774   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: 0033:0x7fd8aba6baa3
RSP: 002b:00007ffe9ff01100 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2d664000
RDX: 0000001b2d624000 RSI: 0000000000600000 RDI: 00007fd8abde0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe9ff01390
 </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
3 locks held by kworker/u4:8/3480:
4 locks held by kworker/u4:10/4183:
 #0: ffff88801a64b938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801a64b938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000e227d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000e227d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff88814e4680e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88814e46ac58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline]
 #3: ffff88814e46ac58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2821
2 locks held by getty/5530:
 #0: ffff888030d820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5762:
 #0: ffff888076c9cda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff888076c9cda0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff888076c9cda0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814e46c990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.1.79/6028:
 #0: ffff88807e22baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88807e22baa0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88807e22baa0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814e46c990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.2.82/6034:
 #0: ffff88807e22a7a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88807e22a7a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88807e22a7a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814e46c990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
1 lock held by udevd/6039:
 #0: ffff888026b2a708 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: prepare_bprm_creds fs/exec.c:1499 [inline]
 #0: ffff888026b2a708 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0xc8/0x1730 fs/exec.c:1854
3 locks held by syz.3.86/6044:
 #0: ffff88801e70e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88801e70e0a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88801e70e0a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814e46c990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.0.87/6045:
 #0: ffff88801e708b20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #0: ffff88801e708b20 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
 #0: ffff88801e708b20 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
 #1: ffff88814e468510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
 #2: ffff88814e46c990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448

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

NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4166 Comm: kworker/u4:9 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:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg+0x60/0x230 arch/x86/kernel/unwind_orc.c:403
Code: 44 24 08 80 3c 28 00 74 05 e8 0c 37 a4 00 4d 8b 77 08 49 8d 7f 10 49 89 fd 49 c1 ed 03 41 80 7c 2d 00 00 74 05 e8 f0 36 a4 00 <4d> 8b 67 10 4c 89 fb 48 c1 eb 03 0f b6 04 2b 84 c0 0f 85 76 01 00
RSP: 0018:ffffc9000e3474c8 EFLAGS: 00000246
RAX: 1ffff92001c68ebe RBX: ffffffff8f10e1ff RCX: ffff88802f23da00
RDX: 0000000000000000 RSI: ffffc9000e347f20 RDI: ffffc9000e3475f8
RBP: dffffc0000000000 R08: ffff88802f23da00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000e347ee8
R13: 1ffff92001c68ebf R14: ffffc9000e340000 R15: ffffc9000e3475e8
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005654ccc94168 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648
 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_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 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:946 [inline]
 skb_free_head net/core/skbuff.c:958 [inline]
 skb_release_data+0x609/0x7f0 net/core/skbuff.c:988
 skb_release_all net/core/skbuff.c:1054 [inline]
 __kfree_skb net/core/skbuff.c:1068 [inline]
 kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1104
 kfree_skb include/linux/skbuff.h:1264 [inline]
 ieee80211_iface_work+0x7a0/0xc90 net/mac80211/iface.c:1717
 cfg80211_wiphy_work+0x228/0x260 net/wireless/core.c:437
 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>