Dear developers and maintainers, We encountered a task hung in function blk_mq_get_tag. It was tested against the latest upstream kernel which was compiled by clang 14. Kernel config and C repro are attached to this email. The bug report is listed below. ``` Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 blk_mq_get_tag+0x509/0xba0 block/blk-mq-tag.c:187 __blk_mq_alloc_requests+0xbc1/0x1710 block/blk-mq.c:499 blk_mq_alloc_request+0x513/0xbc0 block/blk-mq.c:599 scsi_alloc_request drivers/scsi/scsi_lib.c:1229 [inline] scsi_execute_cmd+0x17a/0x1140 drivers/scsi/scsi_lib.c:304 scsi_vpd_inquiry drivers/scsi/scsi.c:312 [inline] scsi_get_vpd_size+0x2e3/0x6b0 drivers/scsi/scsi.c:363 scsi_get_vpd_buf+0x89/0x460 drivers/scsi/scsi.c:433 scsi_attach_vpd+0xdc/0x5e0 drivers/scsi/scsi.c:501 scsi_rescan_device+0xd8/0x290 drivers/scsi/scsi_scan.c:1698 ata_scsi_dev_rescan+0x1fe/0x3c0 drivers/ata/libata-scsi.c:4764 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x9c9/0x14a0 kernel/workqueue.c:3335 worker_thread+0x85c/0xd50 kernel/workqueue.c:3416 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> INFO: task kworker/u10:2:53 blocked for more than 143 seconds. Not tainted 6.9.0-rc6 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:2 state:D stack:21688 pid:53 tgid:53 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 bit_wait_io+0x12/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb0/0x320 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1c7/0x240 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x10c/0xcd0 fs/jbd2/transaction.c:1111 jbd2_journal_get_write_access+0x206/0x250 fs/jbd2/transaction.c:1260 __ext4_journal_get_write_access+0x1e6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_mb_mark_context+0x30f/0xf50 fs/ext4/mballoc.c:4005 ext4_mb_mark_diskspace_used+0x39a/0x8e0 fs/ext4/mballoc.c:4122 ext4_mb_new_blocks+0x132b/0x4210 fs/ext4/mballoc.c:6223 ext4_ext_map_blocks+0x1da8/0x6b00 fs/ext4/extents.c:4317 ext4_map_blocks+0xa8c/0x1cb0 fs/ext4/inode.c:623 mpage_map_one_extent fs/ext4/inode.c:2163 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2216 [inline] ext4_do_writepages+0x16cb/0x3920 fs/ext4/inode.c:2679 ext4_writepages+0x210/0x3c0 fs/ext4/inode.c:2768 do_writepages+0x371/0x830 mm/page-writeback.c:2612 __writeback_single_inode+0xe2/0x660 fs/fs-writeback.c:1650 writeback_sb_inodes+0x831/0x1020 fs/fs-writeback.c:1941 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2012 wb_writeback+0x3c4/0x720 fs/fs-writeback.c:2119 wb_check_old_data_flush fs/fs-writeback.c:2223 [inline] wb_do_writeback fs/fs-writeback.c:2276 [inline] wb_workfn+0xa38/0xf30 fs/fs-writeback.c:2304 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x9c9/0x14a0 kernel/workqueue.c:3335 worker_thread+0x85c/0xd50 kernel/workqueue.c:3416 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> INFO: task kworker/u10:5:2795 blocked for more than 143 seconds. Not tainted 6.9.0-rc6 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:5 state:D stack:21200 pid:2795 tgid:2795 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 blk_mq_get_tag+0x509/0xba0 block/blk-mq-tag.c:187 __blk_mq_alloc_requests+0xbc1/0x1710 block/blk-mq.c:499 blk_mq_get_new_requests block/blk-mq.c:2886 [inline] blk_mq_submit_bio+0xcd2/0x1f00 block/blk-mq.c:2984 __submit_bio+0x23d/0x2e0 block/blk-core.c:621 __submit_bio_noacct_mq block/blk-core.c:700 [inline] submit_bio_noacct_nocheck+0x9e1/0xc40 block/blk-core.c:729 ext4_io_submit+0xd8/0x140 fs/ext4/page-io.c:378 ext4_do_writepages+0x12f2/0x3920 fs/ext4/inode.c:2699 ext4_writepages+0x210/0x3c0 fs/ext4/inode.c:2768 do_writepages+0x371/0x830 mm/page-writeback.c:2612 __writeback_single_inode+0xe2/0x660 fs/fs-writeback.c:1650 writeback_sb_inodes+0x831/0x1020 fs/fs-writeback.c:1941 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2012 wb_writeback+0x3c4/0x720 fs/fs-writeback.c:2119 wb_check_background_flush fs/fs-writeback.c:2189 [inline] wb_do_writeback fs/fs-writeback.c:2277 [inline] wb_workfn+0xaef/0xf30 fs/fs-writeback.c:2304 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x9c9/0x14a0 kernel/workqueue.c:3335 worker_thread+0x85c/0xd50 kernel/workqueue.c:3416 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> INFO: task jbd2/sda-8:4502 blocked for more than 143 seconds. Not tainted 6.9.0-rc6 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda-8 state:D stack:24400 pid:4502 tgid:4502 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 blk_mq_get_tag+0x509/0xba0 block/blk-mq-tag.c:187 __blk_mq_alloc_requests+0xbc1/0x1710 block/blk-mq.c:499 blk_mq_get_new_requests block/blk-mq.c:2886 [inline] blk_mq_submit_bio+0xcd2/0x1f00 block/blk-mq.c:2984 __submit_bio+0x23d/0x2e0 block/blk-core.c:621 __submit_bio_noacct_mq block/blk-core.c:700 [inline] submit_bio_noacct_nocheck+0x9e1/0xc40 block/blk-core.c:729 jbd2_journal_commit_transaction+0x2412/0x5500 fs/jbd2/commit.c:731 kjournald2+0x45f/0x870 fs/jbd2/journal.c:201 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> INFO: task systemd-journal:4529 blocked for more than 143 seconds. Not tainted 6.9.0-rc6 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-journal state:D stack:18872 pid:4529 tgid:4529 ppid:1 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 bit_wait_io+0x12/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb0/0x320 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1c7/0x240 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x10c/0xcd0 fs/jbd2/transaction.c:1111 jbd2_journal_get_write_access+0x206/0x250 fs/jbd2/transaction.c:1260 __ext4_journal_get_write_access+0x1e6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x271/0x360 fs/ext4/inode.c:5731 __ext4_mark_inode_dirty+0x127/0x670 fs/ext4/inode.c:5905 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:5942 __mark_inode_dirty+0x1ef/0x610 fs/fs-writeback.c:2477 generic_update_time fs/inode.c:1907 [inline] inode_update_time fs/inode.c:1920 [inline] __file_update_time fs/inode.c:2109 [inline] file_update_time+0x3d4/0x410 fs/inode.c:2139 ext4_page_mkwrite+0x200/0xde0 fs/ext4/inode.c:6060 do_page_mkwrite+0x18e/0x480 mm/memory.c:3091 wp_page_shared mm/memory.c:3478 [inline] do_wp_page+0x137d/0x26d0 mm/memory.c:3628 handle_pte_fault+0x943/0xd90 mm/memory.c:5316 __handle_mm_fault+0xcdd/0x1230 mm/memory.c:5441 handle_mm_fault+0x3bd/0x880 mm/memory.c:5606 do_user_addr_fault+0xa8b/0x12c0 arch/x86/mm/fault.c:1362 handle_page_fault arch/x86/mm/fault.c:1505 [inline] exc_page_fault+0x7f/0x120 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f3c2a7c5fde RSP: 002b:00007ffeacb5c3f0 EFLAGS: 00010246 RAX: 00007f3c2864ec40 RBX: 00005579abd4c940 RCX: 000000000000acf8 RDX: 0000000000000000 RSI: 00005579abd4c940 RDI: 00007f3c286fdf98 RBP: 00005579abd4c970 R08: 00000000000fdf58 R09: 00000000000fdf58 R10: 0000000000000002 R11: 000000000000c9c8 R12: 0000000000000025 R13: 000000000004d650 R14: 0000000000000000 R15: 00007ffeacb5c410 </TASK> INFO: task rs:main Q:Reg:7643 blocked for more than 143 seconds. Not tainted 6.9.0-rc6 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:rs:main Q:Reg state:D stack:24696 pid:7643 tgid:7606 ppid:1 flags:0x00000000 Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf19/0x15e0 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 io_schedule+0x87/0x100 kernel/sched/core.c:9044 bit_wait_io+0x12/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xb0/0x320 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1c7/0x240 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x10c/0xcd0 fs/jbd2/transaction.c:1111 jbd2_journal_get_write_access+0x206/0x250 fs/jbd2/transaction.c:1260 __ext4_journal_get_write_access+0x1e6/0x6a0 fs/ext4/ext4_jbd2.c:239 ext4_reserve_inode_write+0x271/0x360 fs/ext4/inode.c:5731 __ext4_mark_inode_dirty+0x127/0x670 fs/ext4/inode.c:5905 ext4_dirty_inode+0xc9/0x110 fs/ext4/inode.c:5942 __mark_inode_dirty+0x1ef/0x610 fs/fs-writeback.c:2477 generic_update_time fs/inode.c:1907 [inline] inode_update_time fs/inode.c:1920 [inline] __file_update_time fs/inode.c:2109 [inline] file_modified_flags+0x423/0x490 fs/inode.c:2180 ext4_write_checks+0x24a/0x2c0 fs/ext4/file.c:279 ext4_buffered_write_iter+0xa1/0x340 fs/ext4/file.c:295 ext4_file_write_iter+0x1d1/0x1a10 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa61/0xcf0 fs/read_write.c:590 ksys_write+0x17b/0x2a0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x67/0x6f RIP: 0033:0x7f09137c4fef RSP: 002b:00007f09123ff860 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0900024db0 RCX: 00007f09137c4fef RDX: 000000000000057c RSI: 00007f0900025050 RDI: 0000000000000007 RBP: 000000000000057c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f0900025050 R13: 0000000000000000 R14: 0000000000000083 R15: 00007f0900024db0 </TASK> Showing all locks held in the system: 4 locks held by kworker/1:0/24: #0: ffff888013478948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888013478948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x94f/0x14a0 kernel/workqueue.c:3335 #1: ffffc900001bfd00 ((work_completion)(&(&ap->scsi_rescan_task)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc900001bfd00 ((work_completion)(&(&ap->scsi_rescan_task)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x979/0x14a0 kernel/workqueue.c:3335 #2: ffff88801c4a4360 (&ap->scsi_scan_mutex){+.+.}-{3:3}, at: ata_scsi_dev_rescan+0x3e/0x3c0 drivers/ata/libata-scsi.c:4736 #3: ffff88801cd94378 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #3: ffff88801cd94378 (&dev->mutex){....}-{3:3}, at: scsi_rescan_device+0x32/0x290 drivers/scsi/scsi_scan.c:1684 4 locks held by kworker/u10:1/30: #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x94f/0x14a0 kernel/workqueue.c:3335 #1: ffffc9000083fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc9000083fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x979/0x14a0 kernel/workqueue.c:3335 #2: ffff88801966c0e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1769 [inline] #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1be/0x3c0 fs/ext4/inode.c:2767 1 lock held by khungtaskd/33: #0: ffffffff8dd343e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8dd343e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8dd343e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x54/0x2a0 kernel/locking/lockdep.c:6614 6 locks held by kworker/u10:2/53: #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x94f/0x14a0 kernel/workqueue.c:3335 #1: ffffc900009afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc900009afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x979/0x14a0 kernel/workqueue.c:3335 #2: ffff88801966c0e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1769 [inline] #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1be/0x3c0 fs/ext4/inode.c:2767 #4: ffff888019668950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f81/0x21e0 fs/jbd2/transaction.c:463 #5: ffff888077e08288 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x9b2/0x1cb0 fs/ext4/inode.c:616 4 locks held by kworker/u10:5/2795: #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888060e8f148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x94f/0x14a0 kernel/workqueue.c:3335 #1: ffffc900096ffd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc900096ffd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x979/0x14a0 kernel/workqueue.c:3335 #2: ffff88801966c0e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1769 [inline] #3: ffff88801966ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1be/0x3c0 fs/ext4/inode.c:2767 3 locks held by systemd-journal/4529: #0: ffff88806436c4a8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:677 [inline] #0: ffff88806436c4a8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f7/0x730 mm/memory.c:5762 #1: ffff88801966c518 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1664 [inline] #1: ffff88801966c518 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1829 [inline] #1: ffff88801966c518 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e9/0xde0 fs/ext4/inode.c:6059 #2: ffff888019668950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f81/0x21e0 fs/jbd2/transaction.c:463 1 lock held by in:imklog/7641: 4 locks held by rs:main Q:Reg/7643: #0: ffff888068c299c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x255/0x320 fs/file.c:1191 #1: ffff88801966c420 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2855 [inline] #1: ffff88801966c420 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x230/0xcf0 fs/read_write.c:586 #2: ffff888077cc9800 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline] #2: ffff888077cc9800 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_buffered_write_iter+0x96/0x340 fs/ext4/file.c:294 #3: ffff888019668950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f81/0x21e0 fs/jbd2/transaction.c:463 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 33 Comm: khungtaskd Not tainted 6.9.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114 nmi_cpu_backtrace+0x41e/0x450 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x185/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xddb/0xe20 kernel/hung_task.c:380 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 31 Comm: kworker/u9:1 Not tainted 6.9.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:130 [inline] RIP: 0010:___update_load_avg kernel/sched/pelt.c:265 [inline] RIP: 0010:__update_load_avg_cfs_rq+0x5c9/0xa30 kernel/sched/pelt.c:327 Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 30 00 74 0f e8 9d d0 87 00 48 be 00 00 00 00 00 fc ff df 49 8b 86 90 00 00 00 31 d2 48 f7 f5 <48> 89 c3 49 8d be a8 00 00 00 48 89 f8 48 c1 e8 03 80 3c 30 00 74 RSP: 0000:ffffc9000084f670 EFLAGS: 00000046 RAX: 00000000000001de RBX: 00000000000001f7 RCX: 0000000000001400 RDX: 0000000000005d47 RSI: dffffc0000000000 RDI: ffff88804403e790 RBP: 000000000000b7e8 R08: 0000000000000001 R09: 000000000000056a R10: 000000000000016a R11: fffffbfff1e8f856 R12: 0000000000000000 R13: 0000000000067c00 R14: ffff88804403e700 R15: 000000000000b7e8 FS: 0000000000000000(0000) GS:ffff888044000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0904059118 CR3: 000000000db34000 CR4: 0000000000750ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <NMI> </NMI> <TASK> update_cfs_rq_load_avg+0x483/0x570 kernel/sched/fair.c:4640 update_load_avg+0x193/0x1400 kernel/sched/fair.c:4753 dequeue_entity+0x8d/0xc00 kernel/sched/fair.c:5384 dequeue_task_fair+0x18e/0x990 kernel/sched/fair.c:6821 deactivate_task kernel/sched/core.c:2157 [inline] __schedule+0x50f/0x15e0 kernel/sched/core.c:6692 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x147/0x310 kernel/sched/core.c:6838 toggle_allocation_gate+0x15b/0x240 mm/kfence/core.c:828 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x9c9/0x14a0 kernel/workqueue.c:3335 worker_thread+0x85c/0xd50 kernel/workqueue.c:3416 kthread+0x2ed/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:244 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.097 msecs ``` If you have any questions, please contact us. Reported by Yue Sun <samsun1006219@xxxxxxxxx> Reported by xingwei lee <xrivendell7@xxxxxxxxx> Best Regards, Yue
Attachment:
config
Description: Binary data
#define _GNU_SOURCE #include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/prctl.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h> static unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static long syz_mod_param(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4) { int fd, sysfd; char buf[1024], sysbuf[1024], input[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } fd = open(buf, a2, 0); strncpy(sysbuf, (char*)a3, sizeof(sysbuf) - 1); sysbuf[sizeof(sysbuf) - 1] = 0; sysfd = open(sysbuf, O_RDWR, 0); strncpy(input, (char*)a4, sizeof(input) - 1); hash = strchr(input, '\0'); sysfd = write(sysfd, input, hash - input + 1); return fd; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; memcpy((void*)0x20000000, "/dev/sg#\000", 9); memcpy((void*)0x20000080, "/sys/module/sg/parameters/allow_dio\000", 36); memcpy((void*)0x20000040, "100\000", 4); res = -1; res = syz_mod_param(/*dev=*/0x20000000, /*id=*/0, /*flags=*/0, /*file=*/0x20000080, /*buf=*/0x20000040); if (res != -1) r[0] = res; memcpy((void*)0x20000140, "\x02\x00\x00\x00\x00\x00\x00\x00\xa1\x09\x01\xa1\x04\x4a\x76\x68\xd2" "\x25", 18); syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/1, /*arg=*/0x20000140ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); for (procid = 0; procid < 4; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }