INFO: task jbd2/sda1-8:4967 blocked in I/O wait 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:25120 pid:4967 tgid:4967 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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:476 [inline] jbd2_journal_commit_transaction+0x2f6e/0x5c80 fs/jbd2/commit.c:834 kjournald2+0x3bc/0x740 fs/jbd2/journal.c:200 kthread+0x38b/0x480 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:5626 blocked in I/O wait 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:22312 pid:5626 tgid:5626 ppid:5625 task_flags:0x440100 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3856 wp_page_shared mm/memory.c:4262 [inline] do_wp_page+0x1a77/0x4c30 mm/memory.c:4485 handle_pte_fault mm/memory.c:6659 [inline] __handle_mm_fault mm/memory.c:6784 [inline] handle_mm_fault+0x19c9/0x2f80 mm/memory.c:6951 do_user_addr_fault+0xb35/0x1480 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: 0033:0x00007f3d6007df91 RSP: 002b:00007ffc620b6220 EFLAGS: 00010202 RAX: 0000000000000008 RBX: 0000000000000001 RCX: 0000000000000003 RDX: 00007f3d5e18c000 RSI: 0000000000003ba2 RDI: ffffffff866fffff RBP: 00007ffc620b6720 R08: 0000000000001000 R09: 000055556d0e7a38 R10: 00000000000000a6 R11: 000055556d0e7c20 R12: 00007ffc620b6560 R13: 00007ffc620b6350 R14: 585858582e7a7973 R15: 00007ffc620b62a0 INFO: task kworker/u8:20:5951 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:20 state:D stack:21992 pid:5951 tgid:5951 ppid:2 task_flags:0x4248160 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_ext_insert_extent+0x26f5/0x4bf0 fs/ext4/extents.c:2210 ext4_ext_map_blocks+0x15bf/0x5480 fs/ext4/extents.c:4490 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:697 ext4_map_blocks+0xe8e/0x1c60 fs/ext4/inode.c:942 mpage_map_one_extent fs/ext4/inode.c:2505 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2601 [inline] ext4_do_writepages+0x1978/0x44a0 fs/ext4/inode.c:3077 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3171 do_writepages+0x338/0x560 mm/page-writeback.c:2562 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1809 writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2120 __writeback_inodes_wb+0x114/0x250 fs/fs-writeback.c:2196 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2307 wb_check_old_data_flush fs/fs-writeback.c:2411 [inline] wb_do_writeback fs/fs-writeback.c:2490 [inline] wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2518 process_one_work kernel/workqueue.c:3505 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3588 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3669 kthread+0x38b/0x480 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.5.1608:10354 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1608 state:D stack:24680 pid:10354 tgid:10354 ppid:8260 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3856 do_shared_fault mm/memory.c:6155 [inline] do_fault mm/memory.c:6217 [inline] do_pte_missing+0x70f/0x3570 mm/memory.c:4745 handle_pte_fault mm/memory.c:6632 [inline] __handle_mm_fault mm/memory.c:6784 [inline] handle_mm_fault+0x1807/0x2f80 mm/memory.c:6951 do_user_addr_fault+0xb35/0x1480 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: 0033:0x00007fb044674111 RSP: 002b:00007ffcbec2e9f0 EFLAGS: 00010202 RAX: 0000001b30724000 RBX: 0000000000000000 RCX: 00000000003ffde8 RDX: 0000001b30723ffc RSI: 00000000003ffde8 RDI: 00007fb045555700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fb044a12000 R10: 00007fb045555700 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000007d20 R14: ffffffff816de000 R15: 00007fb045555720 INFO: task syz.0.1609:10357 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1609 state:D stack:24680 pid:10357 tgid:10357 ppid:5638 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3856 do_shared_fault mm/memory.c:6155 [inline] do_fault mm/memory.c:6217 [inline] do_pte_missing+0x70f/0x3570 mm/memory.c:4745 handle_pte_fault mm/memory.c:6632 [inline] __handle_mm_fault mm/memory.c:6784 [inline] handle_mm_fault+0x1807/0x2f80 mm/memory.c:6951 do_user_addr_fault+0xb35/0x1480 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: 0033:0x00007f7f7ae74111 RSP: 002b:00007ffc638e5c10 EFLAGS: 00010202 RAX: 0000001b2d024000 RBX: 0000000000000000 RCX: 00000000003ffde8 RDX: 0000001b2d023ffc RSI: 00000000003ffde8 RDI: 00007f7f7bd55700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f7f7b212000 R10: 00007f7f7bd55700 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000004b2e R14: ffffffff816ddefe R15: 00007f7f7bd55720 INFO: task syz.2.1612:10361 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1612 state:D stack:26112 pid:10361 tgid:10361 ppid:5641 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] file_update_time_flags+0x399/0x440 fs/inode.c:2494 ext4_page_mkwrite+0x21f/0x1470 fs/ext4/inode.c:7864 do_page_mkwrite+0x147/0x310 mm/memory.c:3856 do_shared_fault mm/memory.c:6155 [inline] do_fault mm/memory.c:6217 [inline] do_pte_missing+0x70f/0x3570 mm/memory.c:4745 handle_pte_fault mm/memory.c:6632 [inline] __handle_mm_fault mm/memory.c:6784 [inline] handle_mm_fault+0x1807/0x2f80 mm/memory.c:6951 do_user_addr_fault+0xb35/0x1480 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: 0033:0x00007fc754e6c7c3 RSP: 002b:00007ffc37219850 EFLAGS: 00010246 RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b2ce64000 RDX: 0000001b2ce24000 RSI: 0000000000400000 RDI: 00007fc7551e8708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc37219ae0 INFO: task syz.1.1611:10362 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1611 state:D stack:26768 pid:10362 tgid:10362 ppid:5639 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] touch_atime+0x568/0x670 fs/inode.c:2339 file_accessed include/linux/fs.h:2283 [inline] ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 vfs_mmap_prepare include/linux/fs.h:2075 [inline] call_mmap_prepare mm/vma.c:2986 [inline] __mmap_region mm/vma.c:3103 [inline] mmap_region+0x1191/0x2820 mm/vma.c:3201 do_mmap+0xe0a/0x1300 mm/mmap.c:573 vm_mmap_pgoff+0x27a/0x520 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x00007f9af799f882 RSP: 002b:00007ffd074eea38 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b2cd64000 RCX: 00007f9af799f882 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b2cd64000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000154 R13: 00000000000927c0 R14: 00000000000414dd R15: 00007ffd074eed10 INFO: task syz.4.1613:10363 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1613 state:D stack:26936 pid:10363 tgid:10363 ppid:5637 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5583 [inline] __schedule+0x17dd/0x5830 kernel/sched/core.c:7382 __schedule_loop kernel/sched/core.c:7459 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7474 io_schedule+0x7f/0xd0 kernel/sched/core.c:8146 bit_wait_io+0x13/0x110 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x300 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+0x658/0x10c0 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xec/0x620 fs/ext4/ext4_jbd2.c:253 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:7451 __ext4_mark_inode_dirty+0x141/0x7e0 fs/ext4/inode.c:7642 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:7679 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2751 generic_update_time fs/inode.c:2264 [inline] touch_atime+0x568/0x670 fs/inode.c:2339 file_accessed include/linux/fs.h:2283 [inline] ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 vfs_mmap_prepare include/linux/fs.h:2075 [inline] call_mmap_prepare mm/vma.c:2986 [inline] __mmap_region mm/vma.c:3103 [inline] mmap_region+0x1191/0x2820 mm/vma.c:3201 do_mmap+0xe0a/0x1300 mm/mmap.c:573 vm_mmap_pgoff+0x27a/0x520 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x00007f5dc859f882 RSP: 002b:00007ffd6d425118 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b2d064000 RCX: 00007f5dc859f882 RDX: 0000000000000003 RSI: 00000000005c0000 RDI: 0000001b2d064000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000150 R13: 00000000000927c0 R14: 00000000000414e0 R15: 00007ffd6d4253f0 Showing all locks held in the system: locks held by pr/ttyS0/34: 2, last CPU#1: #0: ffffffff90034078 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff90034078 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline] #0: ffffffff90034078 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff9c215f58 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline] #1: ffffffff9c215f58 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413 locks held by khungtaskd/35: 1, last CPU#0: #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by klogd/4994: 2, last CPU#0: #0: ffffffff902b1e10 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:213 [inline] #0: ffffffff902b1e10 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:320 #1: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #1: ffffffff9015a560 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by getty/5393: 2, on CPU#0: #0: ffff8880280d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5626: 3, on CPU#0: #0: ffff88807496b808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by kworker/u8:20/5951: 6, on CPU#1: #0: ffff888021ed5150 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888021ed5150 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888021ed5150 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline] #0: ffff888021ed5150 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588 #1: ffffc90003367c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90003367c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90003367c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3470 [inline] #1: ffffc90003367c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3588 #2: ffff888036806100 (&type->s_umount_key#35){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:642 #3: ffff888036d20cd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3170 #4: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 #5: ffff888077658218 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0xacb/0x1c60 fs/ext4/inode.c:926 locks held by syz.5.1608/10354: 3, on CPU#0: #0: ffff88805bd46808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.0.1609/10357: 3, on CPU#1: #0: ffff888059d7b948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.2.1612/10361: 3, on CPU#1: #0: ffff88805bd46a88 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:339 #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888036806570 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fe/0x1470 fs/ext4/inode.c:7863 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.1.1611/10362: 3, on CPU#0: #0: ffff888036de0340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline] #0: ffff888036de0340 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1ed/0x520 mm/util.c:579 #1: ffff888036806478 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2283 [inline] #1: ffff888036806478 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.4.1613/10363: 3, on CPU#0: #0: ffff888036de2800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline] #0: ffff888036de2800 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1ed/0x520 mm/util.c:579 #1: ffff888036806478 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2283 [inline] #1: ffff888036806478 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:919 #2: ffff888036804950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 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:377 [inline] watchdog+0x1073/0x10f0 kernel/hung_task.c:598 kthread+0x38b/0x480 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 34 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425 Code: e8 7e 7b 41 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ff c5 b9 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:ffffc90000aa78b8 EFLAGS: 00000002 RAX: 1ffffffff3842b00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff8587b6a0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9c215f80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881234f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e4dcd55660 CR3: 000000000ff48000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:134 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline] wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline] __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline] serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271 kthread+0x38b/0x480 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