INFO: task kworker/u8:3:57 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:20192 pid:57 tgid:57 ppid:2 task_flags:0x4248160 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 rq_qos_wait+0x269/0x360 block/blk-rq-qos.c:307 __wbt_wait block/blk-wbt.c:598 [inline] wbt_wait+0x326/0x550 block/blk-wbt.c:658 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66 rq_qos_throttle block/blk-rq-qos.h:164 [inline] blk_mq_get_new_requests block/blk-mq.c:3032 [inline] blk_mq_submit_bio+0x154a/0x2aa0 block/blk-mq.c:3170 __submit_bio_noacct_mq block/blk-core.c:756 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline] ext4_io_submit fs/ext4/page-io.c:396 [inline] io_submit_add_bh fs/ext4/page-io.c:452 [inline] ext4_bio_write_folio+0xf90/0x1780 fs/ext4/page-io.c:547 mpage_process_page_bufs+0x6bd/0x8a0 fs/ext4/inode.c:2201 mpage_prepare_extent_to_map+0xf92/0x1890 fs/ext4/inode.c:2743 ext4_do_writepages+0xb8d/0x4770 fs/ext4/inode.c:2884 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3032 do_writepages+0x338/0x560 mm/page-writeback.c:2560 __writeback_single_inode+0x136/0x1230 fs/fs-writeback.c:1788 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2099 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2175 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2286 wb_check_old_data_flush fs/fs-writeback.c:2390 [inline] wb_do_writeback fs/fs-writeback.c:2469 [inline] wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2497 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:4913 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25032 pid:4913 tgid:4913 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_buffer include/linux/buffer_head.h:418 [inline] jbd2_journal_commit_transaction+0x2f26/0x5ba0 fs/jbd2/commit.c:834 kjournald2+0x3bc/0x750 fs/jbd2/journal.c:200 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:5572 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21920 pid:5572 tgid:5572 ppid:5571 task_flags:0x440100 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 wp_page_shared mm/memory.c:4217 [inline] do_wp_page+0x20a7/0x3d20 mm/memory.c:4440 handle_pte_fault mm/memory.c:6582 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xd69/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fa1c525c6e2 RSP: 002b:00007ffff23a09b0 EFLAGS: 00010202 RAX: 00007fa1c32c8000 RBX: 000055558f5ca8a0 RCX: 0000000000000004 RDX: 00000000000032a6 RSI: 000055558f633f58 RDI: 0000000000000010 RBP: 00007ffff23a0eb0 R08: 000055558f6346e0 R09: 000000000000009b R10: 0000000040000000 R11: 0000000000000001 R12: 00007ffff23a0cf0 R13: 00007ffff23a0ae0 R14: 585858582e7a7973 R15: 00007ffff23a0a30 INFO: task syz.5.21044:19851 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.21044 state:D stack:24872 pid:19851 tgid:19851 ppid:7014 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f598f202809 RSP: 002b:00007fff29ef6e40 EFLAGS: 00010202 RAX: 0000001b32924000 RBX: 0000000000000000 RCX: 00000000005ffde8 RDX: 0000001b32923ffc RSI: 00000000005ffde8 RDI: 00007f59900e5700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f598f5a2000 R10: 00007f59900e5700 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000007ffff R14: ffffffff81befac7 R15: 00007f59900e5720 INFO: task syz.7.21050:19868 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.21050 state:D stack:24440 pid:19868 tgid:19868 ppid:15389 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f522e222f32 RSP: 002b:00007ffe3a271940 EFLAGS: 00010202 RAX: 0000000000001008 RBX: 00007f522f105720 RCX: 0000000000000000 RDX: 0000001b2df23000 RSI: 0000000000000008 RDI: 00007f522f105720 RBP: 00000000000007b0 R08: 00007f522e5c0000 R09: 00007f522e5d6038 R10: 0000000000000003 R11: 0000000000000002 R12: ffffffff84d4df8c R13: 00007f522e5d6038 R14: 0000000000000060 R15: fffffffffffff000 INFO: task syz.0.21052:19869 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.21052 state:D stack:25272 pid:19869 tgid:19869 ppid:5584 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7ff3a6a52809 RSP: 002b:00007ffecaa06430 EFLAGS: 00010202 RAX: 0000001b31d24000 RBX: 0000000000000000 RCX: 00000000005ffde8 RDX: 0000001b31d23ffc RSI: 00000000005ffde8 RDI: 00007ff3a7935700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ff3a6df2000 R10: 00007ff3a7935700 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000001f4 R14: ffffffff816d5820 R15: 00007ff3a7935720 INFO: task syz.6.21053:19875 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.21053 state:D stack:26056 pid:19875 tgid:19875 ppid:7722 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7ff76a89baa3 RSP: 002b:00007fff68b19410 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2ef64000 RDX: 0000001b2ef24000 RSI: 0000000000600000 RDI: 00007ff76ac10708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fff68b196a0 INFO: task syz.4.21054:19876 blocked in I/O wait for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.21054 state:D stack:26056 pid:19876 tgid:19876 ppid:5585 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 io_schedule+0x80/0xe0 kernel/sched/core.c:8213 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6514 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6699 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6736 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6902 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f601744baa3 RSP: 002b:00007ffe50763810 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b31b64000 RDX: 0000001b31b24000 RSI: 0000000000600000 RDI: 00007f60177c0708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe50763aa0 Showing all locks held in the system: locks held by pr/ttyS0/17: 3, last CPU#0: #0: ffffffff8e09d7b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8e09d7b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff8e09d7b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff99ea21f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_emit_one kernel/printk/nbcon.c:1137 [inline] #1: ffffffff99ea21f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_kthread_func+0x64c/0x880 kernel/printk/nbcon.c:1271 #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by khungtaskd/37: 1, last CPU#1: #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:3/57: 4, on CPU#0: #0: ffff88801f2de938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801f2de938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801f2de938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801f2de938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000123fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000123fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000123fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000123fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff8880362ca0e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:674 #3: ffff8880362d8d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff8880362d8d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1887 [inline] #3: ffff8880362d8d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3031 locks held by kworker/0:3/4967: 3, last CPU#0: #0: ffff88813ff26538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff26538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff26538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff26538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000415fc40 ((gc_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000415fc40 ((gc_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000415fc40 ((gc_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000415fc40 ((gc_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by getty/5342: 2, on CPU#0: #0: ffff88801c6b10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044d62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5572: 3, on CPU#1: #0: ffff88803f942808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.5.21044/19851: 3, on CPU#0: #0: ffff888032f4a1c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.7.21050/19868: 3, on CPU#1: #0: ffff88806e8c7088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.0.21052/19869: 3, on CPU#1: #0: ffff88805f151d08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.6.21053/19875: 3, on CPU#1: #0: ffff888025d8bd08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.4.21054/19876: 3, on CPU#0: #0: ffff88805e4f7088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880362ca688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6901 #2: ffff8880362e6bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 1e fa 64 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6f e7 d0 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001678b8 EFLAGS: 00000202 RAX: 1ffffffff33d4400 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8561a0f0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99ea2220 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125bcb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561d37e81168 CR3: 000000000dfb0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:2013 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline] __serial8250_console_fifo_write+0xd0/0x3f0 drivers/tty/serial/8250/8250_port.c:3345 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xac5/0x1230 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245