syzbot

======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-00603-g3d3a9c8b89d4 #0 Not tainted
------------------------------------------------------
syz.7.13546/6906 is trying to acquire lock:
ffff888035d46360 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault mm/memory.c:6751 [inline]
ffff888035d46360 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xe3/0x190 mm/memory.c:6744

but task is already holding lock:
ffff888025bfa670 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:735

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (
&q->debugfs_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
       blk_mq_init_sched+0x42b/0x640 block/blk-mq-sched.c:473
       elevator_init_mq+0x2cd/0x420 block/elevator.c:610
       add_disk_fwnode+0x113/0x1300 block/genhd.c:413
       sd_probe+0xa86/0x1000 drivers/scsi/sd.c:4024
       call_driver_probe drivers/base/dd.c:579 [inline]
       really_probe+0x23e/0xa90 drivers/base/dd.c:658
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
       __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
       bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
       async_run_entry_fn+0x9c/0x530 kernel/async.c:129
       process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #4 (&q->q_usage_counter(queue)#50){++++}-{0:0}:
       blk_queue_enter+0x50f/0x640 block/blk-core.c:328
       blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:652
       scsi_alloc_request drivers/scsi/scsi_lib.c:1225 [inline]
       scsi_execute_cmd+0x1da/0xf40 drivers/scsi/scsi_lib.c:307
       read_capacity_16+0x213/0xe10 drivers/scsi/sd.c:2655
       sd_read_capacity drivers/scsi/sd.c:2824 [inline]
       sd_revalidate_disk.isra.0+0x1a06/0xa8d0 drivers/scsi/sd.c:3734
       sd_probe+0x904/0x1000 drivers/scsi/sd.c:4010
       call_driver_probe drivers/base/dd.c:579 [inline]
       really_probe+0x23e/0xa90 drivers/base/dd.c:658
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
       __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
       bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
       async_run_entry_fn+0x9c/0x530 kernel/async.c:129
       process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #3 (&q->limits_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
       queue_limits_start_update include/linux/blkdev.h:947 [inline]
       __nbd_set_size+0x2c0/0x730 drivers/block/nbd.c:351
       nbd_set_size drivers/block/nbd.c:388 [inline]
       nbd_start_device+0x8fd/0xd70 drivers/block/nbd.c:1456
       nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline]
       __nbd_ioctl drivers/block/nbd.c:1539 [inline]
       nbd_ioctl+0x21a/0xfd0 drivers/block/nbd.c:1579
       blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl fs/ioctl.c:892 [inline]
       __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&q->q_usage_counter(io)#55){++++}-{0:0}:
       bio_queue_enter block/blk.h:75 [inline]
       blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3090
       __submit_bio+0x384/0x540 block/blk-core.c:629
       __submit_bio_noacct_mq block/blk-core.c:710 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739
       submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868
       submit_bh fs/buffer.c:2819 [inline]
       block_read_full_folio+0x812/0xa50 fs/buffer.c:2446
       filemap_read_folio+0xc6/0x2a0 mm/filemap.c:2357
       filemap_update_page mm/filemap.c:2441 [inline]
       filemap_get_pages+0x155f/0x1be0 mm/filemap.c:2562
       filemap_read+0x3ca/0xd70 mm/filemap.c:2637
       blkdev_read_iter+0x187/0x480 block/fops.c:770
       new_sync_read fs/read_write.c:484 [inline]
       vfs_read+0x87f/0xbe0 fs/read_write.c:565
       ksys_read+0x12b/0x250 fs/read_write.c:708
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (mapping.invalidate_lock#2){++++}-{4:4}:
       down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:886 [inline]
       filemap_fault+0x62c/0x2820 mm/filemap.c:3342
       __do_fault+0x10a/0x490 mm/memory.c:4907
       do_read_fault mm/memory.c:5322 [inline]
       do_fault mm/memory.c:5456 [inline]
       do_pte_missing+0xebd/0x3e00 mm/memory.c:3979
       handle_pte_fault mm/memory.c:5801 [inline]
       __handle_mm_fault+0x103c/0x2a40 mm/memory.c:5944
       handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6112
       faultin_page mm/gup.c:1196 [inline]
       __get_user_pages+0x8d9/0x3b50 mm/gup.c:1494
       populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1932
       __mm_populate+0x1d6/0x380 mm/gup.c:2035
       do_mlock+0x40a/0x7d0 mm/mlock.c:653
       __do_sys_mlock mm/mlock.c:661 [inline]
       __se_sys_mlock mm/mlock.c:659 [inline]
       __x64_sys_mlock+0x59/0x80 mm/mlock.c:659
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
       __might_fault mm/memory.c:6751 [inline]
       __might_fault+0x11b/0x190 mm/memory.c:6744
       _inline_copy_from_user include/linux/uaccess.h:162 [inline]
       _copy_from_user+0x29/0xd0 lib/usercopy.c:18
       copy_from_user include/linux/uaccess.h:212 [inline]
       __blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626
       blk_trace_ioctl+0x163/0x290 kernel/trace/blktrace.c:740
       blkdev_ioctl+0x109/0x6d0 block/ioctl.c:682
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl fs/ioctl.c:892 [inline]
       __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> &q->q_usage_counter(queue)#50 --> &q->debugfs_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->debugfs_mutex);
                               lock(&q->q_usage_counter(queue)#50);
                               lock(&q->debugfs_mutex);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz.7.13546/6906:
 #0: ffff888025bfa670 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0xc9/0x290 kernel/trace/blktrace.c:735

stack backtrace:
CPU: 0 UID: 0 PID: 6906 Comm: syz.7.13546 Not tainted 6.13.0-syzkaller-00603-g3d3a9c8b89d4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
 __might_fault mm/memory.c:6751 [inline]
 __might_fault+0x11b/0x190 mm/memory.c:6744
 _inline_copy_from_user include/linux/uaccess.h:162 [inline]
 _copy_from_user+0x29/0xd0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 __blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626
 blk_trace_ioctl+0x163/0x290 kernel/trace/blktrace.c:740
 blkdev_ioctl+0x109/0x6d0 block/ioctl.c:682
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb5f185d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb5ffa1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007feb5f375fa0 RCX: 00007feb5f185d29
RDX: 00000000200000c0 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007feb5f201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feb5f375fa0 R15: 00007ffd24cf6c58
 </TASK>