Dev nbd2: unable to read RDB block 0
 nbd2: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd2: unable to read RDB block 0
 nbd2: unable to read partition table
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 Tainted: G     U            
------------------------------------------------------
udevd/2264 is trying to acquire lock:
ffff888144335358 (&q->q_usage_counter(io)#51){++++}-{0:0}, at: __submit_bio+0x3d1/0x690 block/blk-core.c:628

but task is already holding lock:
ffff8880238d2040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
ffff8880238d2040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_unbounded+0x173/0x7d0 mm/readahead.c:229

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (mapping.invalidate_lock#2){++++}-{4:4}:
       down_read+0x9a/0x330 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
       filemap_fault+0x1845/0x2ca0 mm/filemap.c:3454
       __do_fault+0x10a/0x490 mm/memory.c:4988
       do_read_fault mm/memory.c:5403 [inline]
       do_fault mm/memory.c:5537 [inline]
       do_pte_missing+0xecf/0x3e10 mm/memory.c:4058
       handle_pte_fault mm/memory.c:5900 [inline]
       __handle_mm_fault+0x1166/0x2c60 mm/memory.c:6043
       handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6212
       faultin_page mm/gup.c:1196 [inline]
       __get_user_pages+0x773/0x36f0 mm/gup.c:1491
       populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1929
       __mm_populate+0x1d6/0x380 mm/gup.c:2032
       mm_populate include/linux/mm.h:3386 [inline]
       vm_mmap_pgoff+0x2d3/0x3a0 mm/util.c:580
       ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:607
       __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
       __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
       __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
       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:6851 [inline]
       __might_fault+0x11b/0x190 mm/memory.c:6844
       _copy_from_iter+0x1c4/0x1560 lib/iov_iter.c:259
       copy_from_iter include/linux/uio.h:228 [inline]
       copy_from_iter_full include/linux/uio.h:245 [inline]
       skb_do_copy_data_nocache include/net/sock.h:2197 [inline]
       skb_copy_to_page_nocache include/net/sock.h:2223 [inline]
       tcp_sendmsg_locked+0x1979/0x37c0 net/ipv4/tcp.c:1222
       tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1358
       inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851
       sock_sendmsg_nosec net/socket.c:718 [inline]
       __sock_sendmsg net/socket.c:733 [inline]
       sock_write_iter+0x4ac/0x5b0 net/socket.c:1137
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0x5ae/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

-> #4 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3662
       lock_sock include/net/sock.h:1624 [inline]
       inet_shutdown+0x67/0x440 net/ipv4/af_inet.c:905
       nbd_mark_nsock_dead+0xae/0x5d0 drivers/block/nbd.c:318
       sock_shutdown+0x17c/0x280 drivers/block/nbd.c:411
       nbd_clear_sock drivers/block/nbd.c:1416 [inline]
       nbd_config_put+0x1e6/0x750 drivers/block/nbd.c:1440
       nbd_genl_connect+0x12d5/0x1c00 drivers/block/nbd.c:2226
       genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115
       genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
       genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210
       netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2533
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
       netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
       netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338
       netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882
       sock_sendmsg_nosec net/socket.c:718 [inline]
       __sock_sendmsg net/socket.c:733 [inline]
       ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
       ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
       __sys_sendmsg+0x16e/0x220 net/socket.c:2659
       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

-> #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+0x443/0x1dc0 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_hw_queue+0x239/0x670 block/blk-mq.c:2354
       blk_mq_dispatch_plug_list block/blk-mq.c:2866 [inline]
       blk_mq_flush_plug_list+0x673/0x1c60 block/blk-mq.c:2917
       __blk_flush_plug+0x2c5/0x4b0 block/blk-core.c:1213
       blk_finish_plug block/blk-core.c:1240 [inline]
       blk_finish_plug block/blk-core.c:1237 [inline]
       __submit_bio+0x547/0x690 block/blk-core.c:642
       __submit_bio_noacct_mq block/blk-core.c:715 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744
       submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867
       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:2390
       do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3960
       read_mapping_folio include/linux/pagemap.h:1023 [inline]
       read_part_sector+0xd4/0x310 block/partitions/core.c:722
       adfspart_check_ICS+0x94/0x940 block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x71f/0x1520 block/partitions/core.c:693
       blkdev_get_whole+0x187/0x290 block/bdev.c:706
       bdev_open+0x2c7/0xe20 block/bdev.c:915
       blkdev_open+0x27b/0x3f0 block/fops.c:652
       do_dentry_open+0x735/0x1c40 fs/open.c:956
       vfs_open+0x82/0x3f0 fs/open.c:1086
       do_open fs/namei.c:3830 [inline]
       path_openat+0x1e88/0x2d80 fs/namei.c:3989
       do_filp_open+0x20c/0x470 fs/namei.c:4016
       do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
       do_sys_open fs/open.c:1443 [inline]
       __do_sys_openat fs/open.c:1459 [inline]
       __se_sys_openat fs/open.c:1454 [inline]
       __x64_sys_openat+0x175/0x210 fs/open.c:1454
       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 (&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+0x443/0x1dc0 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_hw_queue+0x239/0x670 block/blk-mq.c:2354
       blk_mq_dispatch_plug_list block/blk-mq.c:2866 [inline]
       blk_mq_flush_plug_list+0x673/0x1c60 block/blk-mq.c:2917
       __blk_flush_plug+0x2c5/0x4b0 block/blk-core.c:1213
       blk_finish_plug block/blk-core.c:1240 [inline]
       blk_finish_plug block/blk-core.c:1237 [inline]
       __submit_bio+0x547/0x690 block/blk-core.c:642
       __submit_bio_noacct_mq block/blk-core.c:715 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744
       submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867
       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:2390
       do_read_cache_folio+0x263/0x5c0 mm/filemap.c:3960
       read_mapping_folio include/linux/pagemap.h:1023 [inline]
       read_part_sector+0xd4/0x310 block/partitions/core.c:722
       adfspart_check_ICS+0x94/0x940 block/partitions/acorn.c:360
       check_partition block/partitions/core.c:141 [inline]
       blk_add_partitions block/partitions/core.c:589 [inline]
       bdev_disk_changed+0x71f/0x1520 block/partitions/core.c:693
       blkdev_get_whole+0x187/0x290 block/bdev.c:706
       bdev_open+0x2c7/0xe20 block/bdev.c:915
       blkdev_open+0x27b/0x3f0 block/fops.c:652
       do_dentry_open+0x735/0x1c40 fs/open.c:956
       vfs_open+0x82/0x3f0 fs/open.c:1086
       do_open fs/namei.c:3830 [inline]
       path_openat+0x1e88/0x2d80 fs/namei.c:3989
       do_filp_open+0x20c/0x470 fs/namei.c:4016
       do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
       do_sys_open fs/open.c:1443 [inline]
       __do_sys_openat fs/open.c:1459 [inline]
       __se_sys_openat fs/open.c:1454 [inline]
       __x64_sys_openat+0x175/0x210 fs/open.c:1454
       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 (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 block/blk-mq.c:308 [inline]
       blk_mq_update_nr_requests+0x288/0x670 block/blk-mq.c:4875
       queue_requests_store+0x161/0x210 block/blk-sysfs.c:74
       queue_attr_store+0x370/0x510 block/blk-sysfs.c:715
       sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139
       kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0x5ae/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

-> #0 (&q->q_usage_counter(io)#51){++++}-{0:0}:
       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
       bio_queue_enter block/blk.h:78 [inline]
       blk_mq_submit_bio+0x20f5/0x2610 block/blk-mq.c:3091
       __submit_bio+0x3d1/0x690 block/blk-core.c:628
       __submit_bio_noacct_mq block/blk-core.c:715 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744
       submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867
       mpage_bio_submit_read fs/mpage.c:75 [inline]
       mpage_readahead+0x41d/0x590 fs/mpage.c:377
       read_pages+0x1a7/0xc60 mm/readahead.c:161
       page_cache_ra_unbounded+0x426/0x7d0 mm/readahead.c:298
       do_page_cache_ra mm/readahead.c:328 [inline]
       force_page_cache_ra+0x24b/0x340 mm/readahead.c:357
       page_cache_sync_ra+0x158/0xa30 mm/readahead.c:585
       filemap_get_pages+0xb62/0x1c30 mm/filemap.c:2580
       filemap_read+0x3c5/0xe70 mm/filemap.c:2691
       blkdev_read_iter+0x187/0x4b0 block/fops.c:796
       new_sync_read fs/read_write.c:484 [inline]
       vfs_read+0x886/0xbf0 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

other info that might help us debug this:

Chain exists of:
  &q->q_usage_counter(io)#51 --> &mm->mmap_lock --> mapping.invalidate_lock#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(mapping.invalidate_lock#2);
                               lock(&mm->mmap_lock);
                               lock(mapping.invalidate_lock#2);
  rlock(&q->q_usage_counter(io)#51);

 *** DEADLOCK ***

1 lock held by udevd/2264:
 #0: ffff8880238d2040 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
 #0: ffff8880238d2040 (mapping.invalidate_lock#2){++++}-{4:4}, at: page_cache_ra_unbounded+0x173/0x7d0 mm/readahead.c:229

stack backtrace:
CPU: 1 UID: 0 PID: 2264 Comm: udevd Tainted: G     U             6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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
 bio_queue_enter block/blk.h:78 [inline]
 blk_mq_submit_bio+0x20f5/0x2610 block/blk-mq.c:3091
 __submit_bio+0x3d1/0x690 block/blk-core.c:628
 __submit_bio_noacct_mq block/blk-core.c:715 [inline]
 submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:744
 submit_bio_noacct+0x50d/0x1ec0 block/blk-core.c:867
 mpage_bio_submit_read fs/mpage.c:75 [inline]
 mpage_readahead+0x41d/0x590 fs/mpage.c:377
 read_pages+0x1a7/0xc60 mm/readahead.c:161
 page_cache_ra_unbounded+0x426/0x7d0 mm/readahead.c:298
 do_page_cache_ra mm/readahead.c:328 [inline]
 force_page_cache_ra+0x24b/0x340 mm/readahead.c:357
 page_cache_sync_ra+0x158/0xa30 mm/readahead.c:585
 filemap_get_pages+0xb62/0x1c30 mm/filemap.c:2580
 filemap_read+0x3c5/0xe70 mm/filemap.c:2691
 blkdev_read_iter+0x187/0x4b0 block/fops.c:796
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x886/0xbf0 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
RIP: 0033:0x7fdc00316b6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff9823a428 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00001fffffff0000 RCX: 00007fdc00316b6a
RDX: 0000000000000040 RSI: 000055aa77eb5828 RDI: 0000000000000009
RBP: 0000000000000040 R08: 000055aa77eb5800 R09: 0000000000000040
R10: 0000000000000015 R11: 0000000000000246 R12: 000055aa77eb5800
R13: 000055aa77eb5818 R14: 000055aa77ea5ec8 R15: 000055aa77ea5e70
 </TASK>