INFO: task kworker/u4:2:34 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:22544 pid:34 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: 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 rq_qos_wait+0x22b/0x360 block/blk-rq-qos.c:282 __wbt_wait block/blk-wbt.c:595 [inline] wbt_wait+0x34a/0x580 block/blk-wbt.c:659 __rq_qos_throttle+0x65/0xb0 block/blk-rq-qos.c:66 rq_qos_throttle block/blk-rq-qos.h:151 [inline] blk_mq_get_new_requests block/blk-mq.c:2955 [inline] blk_mq_submit_bio+0x8fb/0x2220 block/blk-mq.c:3056 __submit_bio+0x12b/0x260 block/blk-core.c:610 __submit_bio_noacct_mq block/blk-core.c:689 [inline] submit_bio_noacct_nocheck+0x6e8/0x9c0 block/blk-core.c:718 ext4_io_submit fs/ext4/page-io.c:389 [inline] io_submit_add_bh fs/ext4/page-io.c:430 [inline] ext4_bio_write_folio+0x16a4/0x22d0 fs/ext4/page-io.c:578 mpage_submit_folio+0x231/0x3c0 fs/ext4/inode.c:1911 mpage_process_page_bufs+0x6bf/0x8c0 fs/ext4/inode.c:2024 mpage_prepare_extent_to_map+0xdd3/0x1d50 fs/ext4/inode.c:2532 ext4_do_writepages+0xb46/0x3990 fs/ext4/inode.c:2674 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2810 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_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xad7/0xe60 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 INFO: task jbd2/sda1-8:5102 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:25736 pid:5102 ppid:2 flags:0x00004000 Call Trace: 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 INFO: task syz-executor:5763 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:22168 pid:5763 ppid:5762 flags:0x00004002 Call Trace: 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:5933 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144 __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:6262 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: 0033:0x7f652f0701e3 RSP: 002b:00007ffd684b2a40 EFLAGS: 00010206 RAX: 00007f6528ffff80 RBX: 00007ffd684b2b70 RCX: 0000000000000000 RDX: 00007f6528ffff7c RSI: 0000000000000008 RDI: 00007ffd684b2b70 RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffd684b2b50 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000080 R14: ffffffffffffff80 R15: 0000000000000000 INFO: task syz.3.3030:14549 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3030 state:D stack:27048 pid:14549 ppid:5778 flags:0x00004004 Call Trace: 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:5933 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144 __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:6262 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: 0033:0x7fdfa7272f32 RSP: 002b:00007ffca26b0d40 EFLAGS: 00010202 RAX: 0000000000003008 RBX: 00007fdfa8155720 RCX: 0000000000000000 RDX: 0000001b2df21000 RSI: 0000000000000008 RDI: 00007fdfa8155720 RBP: 00000000000006b8 R08: 00007fdfa7610000 R09: 00007fdfa7626038 R10: 0000000000000007 R11: 0000000000000002 R12: ffffffff8a7b3d1a R13: 00007fdfa7626038 R14: 00000000000001c3 R15: ffffffffffffd000 INFO: task syz.5.3031:14561 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.3031 state:D stack:25688 pid:14561 ppid:10220 flags:0x00004004 Call Trace: 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:5933 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144 __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:6262 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: 0033:0x7f1715e6baa3 RSP: 002b:00007ffdd63ef3b0 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b32464000 RDX: 0000001b32424000 RSI: 0000000000600000 RDI: 00007f17161e0708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffdd63ef640 INFO: task syz.1.3032:14563 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3032 state:D stack:27560 pid:14563 ppid:5774 flags:0x00004004 Call Trace: 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:5933 __ext4_mark_inode_dirty+0x13f/0x6d0 fs/ext4/inode.c:6107 ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6144 __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:6262 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: 0033:0x7f649a66baa3 RSP: 002b:00007ffc3f10c070 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2d764000 RDX: 0000001b2d724000 RSI: 0000000000600000 RDI: 00007f649a9e0708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc3f10c300 Showing all locks held in the system: 5 locks held by kworker/u4:1/12: 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:6633 4 locks held by kworker/u4:2/34: #0: ffff88801a67f938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff88801a67f938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc90000aafd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc90000aafd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #2: ffff88814e26a0e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607 #3: ffff88814e26cc58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] #3: ffff88814e26cc58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2809 2 locks held by kworker/u4:8/1323: 2 locks held by getty/5531: #0: ffff88802cf4e0a0 (&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/5763: #0: ffff88807d2c3aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff88807d2c3aa0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline] #0: ffff88807d2c3aa0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440 #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261 #2: ffff88814e26e990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448 3 locks held by syz.3.3030/14549: #0: ffff8880218627a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff8880218627a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline] #0: ffff8880218627a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440 #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261 #2: ffff88814e26e990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448 3 locks held by syz.5.3031/14561: #0: ffff88807ec801a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff88807ec801a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline] #0: ffff88807ec801a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440 #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261 #2: ffff88814e26e990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448 3 locks held by syz.1.3032/14563: #0: ffff88807e244420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline] #0: ffff88807e244420 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline] #0: ffff88807e244420 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440 #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline] #1: ffff88814e26a510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6261 #2: ffff88814e26e990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448 ============================================= 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: 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1323 Comm: kworker/u4:8 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:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline] RIP: 0010:deref_stack_reg+0x8f/0x230 arch/x86/kernel/unwind_orc.c:403 Code: 89 fb 48 c1 eb 03 0f b6 04 2b 84 c0 0f 85 76 01 00 00 41 8b 2f 31 ff 89 ee e8 7d a5 4b 00 85 ed 0f 95 c0 48 8b 2c 24 49 39 ee <0f> 96 c1 20 c1 49 39 ec 0f 97 c0 84 c1 74 1e 48 8d 45 08 4c 39 f0 RSP: 0018:ffffc90005127588 EFLAGS: 00000297 RAX: ffffffff813be001 RBX: 1ffff92000a24ed5 RCX: 0000000000000000 RDX: ffff8880247b1e00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005127ed8 R08: ffff8880247b1e00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90005128000 R13: 1ffff92000a24ed7 R14: ffffc90005120000 R15: ffffc900051276a8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558a1211c168 CR3: 000000000cf32000 CR4: 00000000003506e0 Call Trace: 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+0xf8/0x290 mm/slub.c:3852 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x723/0xa90 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