syzbot

======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-01268-gc0e75905caf3 #0 Not tainted
------------------------------------------------------
syz.1.5838/27584 is trying to acquire lock:
ffff88802894a330 (&q->sysfs_lock){+.+.}-{4:4}, at: blk_register_queue+0x132/0x4f0 block/blk-sysfs.c:778

but task is already holding lock:
ffff88802894a3c0 (&q->sysfs_dir_lock){+.+.}-{4:4}, at: blk_register_queue+0x5c/0x4f0 block/blk-sysfs.c:767

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (&q->sysfs_dir_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       blk_mq_sysfs_unregister_hctxs+0x92/0x2d0 block/blk-mq-sysfs.c:278
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5019 [inline]
       blk_mq_update_nr_hw_queues+0x8c1/0x1290 block/blk-mq.c:5065
       nbd_start_device+0x172/0xcc0 drivers/block/nbd.c:1475
       nbd_start_device_ioctl drivers/block/nbd.c:1526 [inline]
       __nbd_ioctl drivers/block/nbd.c:1601 [inline]
       nbd_ioctl+0x21a/0xd60 drivers/block/nbd.c:1641
       blkdev_ioctl+0x279/0x6d0 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+0x193/0x200 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

-> #7 (&q->q_usage_counter(io)#49){++++}-{0:0}:
       bio_queue_enter block/blk.h:77 [inline]
       blk_mq_submit_bio+0x20db/0x25f0 block/blk-mq.c:3091
       __submit_bio+0x3d1/0x690 block/blk-core.c:629
       __submit_bio_noacct_mq block/blk-core.c:716 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:745
       submit_bio_noacct+0x50d/0x1ec0 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+0xc9/0x2a0 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:795
       new_sync_read fs/read_write.c:484 [inline]
       vfs_read+0x882/0xbe0 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

-> #6 (mapping.invalidate_lock#2){++++}-{4:4}:
       down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:887 [inline]
       filemap_fault+0x62c/0x2820 mm/filemap.c:3342
       __do_fault+0x10d/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
       do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
       raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
       copy_from_user_iter lib/iov_iter.c:55 [inline]
       iterate_ubuf include/linux/iov_iter.h:30 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
       iterate_and_advance include/linux/iov_iter.h:328 [inline]
       __copy_from_iter lib/iov_iter.c:249 [inline]
       _copy_from_iter+0x380/0x1560 lib/iov_iter.c:260
       copy_from_iter include/linux/uio.h:228 [inline]
       copy_from_iter_full include/linux/uio.h:245 [inline]
       tipc_msg_build+0x308/0x1120 net/tipc/msg.c:408
       __tipc_sendstream+0x6fa/0x1190 net/tipc/socket.c:1615
       tipc_sendstream+0x4f/0x70 net/tipc/socket.c:1546
       sock_sendmsg_nosec net/socket.c:711 [inline]
       __sock_sendmsg net/socket.c:726 [inline]
       sock_write_iter+0x501/0x5b0 net/socket.c:1147
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0x5b1/0x1150 fs/read_write.c:679
       ksys_write+0x207/0x250 fs/read_write.c:731
       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

-> #5 (&mm->mmap_lock){++++}-{4:4}:
       __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]
       csum_and_copy_from_user include/net/checksum.h:31 [inline]
       copy_from_user_iter_csum net/core/skbuff.c:7272 [inline]
       iterate_ubuf include/linux/iov_iter.h:30 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
       csum_and_copy_from_iter_full+0x218/0x1e20 net/core/skbuff.c:7284
       ip_generic_getfrag+0x175/0x260 net/ipv4/ip_output.c:944
       raw6_getfrag+0x22d/0x2a0 net/ipv6/raw.c:737
       __ip6_append_data.isra.0+0x2dcd/0x45e0 net/ipv6/ip6_output.c:1700
       ip6_append_data+0x1e6/0x500 net/ipv6/ip6_output.c:1852
       rawv6_sendmsg+0x1584/0x4440 net/ipv6/raw.c:919
       inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:851
       sock_sendmsg_nosec net/socket.c:711 [inline]
       __sock_sendmsg net/socket.c:726 [inline]
       ____sys_sendmsg+0x98c/0xc90 net/socket.c:2583
       ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637
       __sys_sendmsg+0x16e/0x220 net/socket.c:2669
       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

-> #4 (sk_lock-AF_INET6){+.+.}-{0:0}:
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3625
       lock_sock include/net/sock.h:1623 [inline]
       inet_shutdown+0x67/0x440 net/ipv4/af_inet.c:905
       nbd_mark_nsock_dead+0xae/0x5d0 drivers/block/nbd.c:318
       recv_work+0x691/0xaa0 drivers/block/nbd.c:1018
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #3 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
       nbd_queue_rq+0x424/0x1220 drivers/block/nbd.c:1204
       blk_mq_dispatch_rq_list+0x446/0x1dc0 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
       __blk_mq_sched_dispatch_requests+0xcdf/0x1620 block/blk-mq-sched.c:309
       blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:331
       blk_mq_run_work_fn+0x135/0x380 block/blk-mq.c:2530
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       nbd_queue_rq+0xbe/0x1220 drivers/block/nbd.c:1196
       blk_mq_dispatch_rq_list+0x446/0x1dc0 block/blk-mq.c:2120
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
       __blk_mq_sched_dispatch_requests+0xcdf/0x1620 block/blk-mq-sched.c:309
       blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:331
       blk_mq_run_work_fn+0x135/0x380 block/blk-mq.c:2530
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3236
       process_scheduled_works kernel/workqueue.c:3317 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync include/linux/srcu.h:176 [inline]
       __synchronize_srcu+0xa9/0x2a0 kernel/rcu/srcutree.c:1418
       blk_mq_wait_quiesce_done block/blk-mq.c:293 [inline]
       blk_mq_wait_quiesce_done block/blk-mq.c:290 [inline]
       blk_mq_quiesce_queue block/blk-mq.c:313 [inline]
       blk_mq_quiesce_queue+0x149/0x1b0 block/blk-mq.c:308
       elevator_disable+0x70/0x490 block/elevator.c:657
       blk_mq_elv_switch_none block/blk-mq.c:4950 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5014 [inline]
       blk_mq_update_nr_hw_queues+0x3a0/0x1290 block/blk-mq.c:5065
       nbd_start_device+0x172/0xcc0 drivers/block/nbd.c:1475
       nbd_start_device_ioctl drivers/block/nbd.c:1526 [inline]
       __nbd_ioctl drivers/block/nbd.c:1601 [inline]
       nbd_ioctl+0x21a/0xd60 drivers/block/nbd.c:1641
       blkdev_ioctl+0x279/0x6d0 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+0x193/0x200 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

-> #0 (&q->sysfs_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain kernel/locking/lockdep.c:3906 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
       blk_register_queue+0x132/0x4f0 block/blk-sysfs.c:778
       add_disk_fwnode+0x8b6/0x1320 block/genhd.c:505
       add_disk include/linux/blkdev.h:759 [inline]
       md_alloc+0x3c2/0x1080 drivers/md/md.c:5909
       md_alloc_and_put drivers/md/md.c:5944 [inline]
       md_probe drivers/md/md.c:5957 [inline]
       md_probe+0x6e/0xd0 drivers/md/md.c:5952
       blk_probe_dev+0x119/0x1a0 block/genhd.c:820
       blk_request_module+0x16/0xb0 block/genhd.c:833
       blkdev_get_no_open+0x7a/0xe0 block/bdev.c:783
       bdev_file_open_by_dev block/bdev.c:1004 [inline]
       bdev_file_open_by_dev+0x6b/0x210 block/bdev.c:992
       swsusp_check+0x74/0x420 kernel/power/swap.c:1569
       software_resume+0x6d/0x400 kernel/power/hibernate.c:993
       resume_store+0x249/0x460 kernel/power/hibernate.c:1271
       kobj_attr_store+0x58/0x80 lib/kobject.c:840
       sysfs_kf_write+0x11a/0x170 fs/sysfs/file.c:139
       kernfs_fop_write_iter+0x340/0x500 fs/kernfs/file.c:334
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0x5b1/0x1150 fs/read_write.c:679
       ksys_write+0x12b/0x250 fs/read_write.c:731
       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:
  &q->sysfs_lock --> &q->q_usage_counter(io)#49 --> &q->sysfs_dir_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->sysfs_dir_lock);
                               lock(&q->q_usage_counter(io)#49);
                               lock(&q->sysfs_dir_lock);
  lock(&q->sysfs_lock);

 *** DEADLOCK ***

8 locks held by syz.1.5838/27584:
 #0: ffff8880351a30b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x267/0x390 fs/file.c:1192
 #1: ffff888030dc6420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:731
 #2: ffff8880217a0488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x27b/0x500 fs/kernfs/file.c:325
 #3: ffff888142290a58 (kn->active#69){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x29e/0x500 fs/kernfs/file.c:326
 #4: ffffffff8e0839a8 (system_transition_mutex){+.+.}-{4:4}, at: software_resume+0x63/0x400 kernel/power/hibernate.c:992
 #5: ffffffff8ecd8c88 (major_names_lock){+.+.}-{4:4}, at: blk_probe_dev+0x25/0x1a0 block/genhd.c:817
 #6: ffffffff8fa5bb88 (disks_mutex){+.+.}-{4:4}, at: md_alloc+0x3e/0x1080 drivers/md/md.c:5857
 #7: ffff88802894a3c0 (&q->sysfs_dir_lock){+.+.}-{4:4}, at: blk_register_queue+0x5c/0x4f0 block/blk-sysfs.c:767

stack backtrace:
CPU: 0 UID: 0 PID: 27584 Comm: syz.1.5838 Not tainted 6.13.0-syzkaller-01268-gc0e75905caf3 #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+0x490/0x760 kernel/locking/lockdep.c:2076
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain kernel/locking/lockdep.c:3906 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730
 blk_register_queue+0x132/0x4f0 block/blk-sysfs.c:778
 add_disk_fwnode+0x8b6/0x1320 block/genhd.c:505
 add_disk include/linux/blkdev.h:759 [inline]
 md_alloc+0x3c2/0x1080 drivers/md/md.c:5909
 md_alloc_and_put drivers/md/md.c:5944 [inline]
 md_probe drivers/md/md.c:5957 [inline]
 md_probe+0x6e/0xd0 drivers/md/md.c:5952
 blk_probe_dev+0x119/0x1a0 block/genhd.c:820
 blk_request_module+0x16/0xb0 block/genhd.c:833
 blkdev_get_no_open+0x7a/0xe0 block/bdev.c:783
 bdev_file_open_by_dev block/bdev.c:1004 [inline]
 bdev_file_open_by_dev+0x6b/0x210 block/bdev.c:992
 swsusp_check+0x74/0x420 kernel/power/swap.c:1569
 software_resume+0x6d/0x400 kernel/power/hibernate.c:993
 resume_store+0x249/0x460 kernel/power/hibernate.c:1271
 kobj_attr_store+0x58/0x80 lib/kobject.c:840
 sysfs_kf_write+0x11a/0x170 fs/sysfs/file.c:139
 kernfs_fop_write_iter+0x340/0x500 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x5b1/0x1150 fs/read_write.c:679
 ksys_write+0x12b/0x250 fs/read_write.c:731
 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: 0033:0x7f4316585d29
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:00007f43143b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4316776160 RCX: 00007f4316585d29
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007f4316601b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4316776160 R15: 00007ffd542c7e58
 </TASK>
PM: Image not found (code -6)