Buffer I/O error on dev nbd4, logical block 0, async page read Dev nbd4: unable to read RDB block 0 nbd4: unable to read partition table ldm_validate_partition_table(): Disk read failed. Dev nbd4: unable to read RDB block 0 nbd4: unable to read partition table ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc4-syzkaller-00295-gb91872c56940 #0 Not tainted ------------------------------------------------------ udevd/17250 is trying to acquire lock: ffff8880259adc88 (&q->q_usage_counter(io)#53){++++}-{0:0}, at: __submit_bio+0x2cf/0x6a0 block/blk-core.c:628 but task is already holding lock: ffff888148c4ce40 (mapping.invalidate_lock#2){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] ffff888148c4ce40 (mapping.invalidate_lock#2){.+.+}-{4:4}, at: page_cache_ra_unbounded+0x156/0x820 mm/readahead.c:229 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (mapping.invalidate_lock#2){.+.+}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] filemap_fault+0x7f8/0x16c0 mm/filemap.c:3435 __do_fault+0x137/0x390 mm/memory.c:4988 do_read_fault mm/memory.c:5403 [inline] do_fault mm/memory.c:5537 [inline] do_pte_missing mm/memory.c:4058 [inline] handle_pte_fault mm/memory.c:5900 [inline] __handle_mm_fault+0x4c44/0x70f0 mm/memory.c:6043 handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6212 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1538 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] _inline_copy_from_user include/linux/uaccess.h:178 [inline] _copy_from_user+0x76/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_from_sockptr_offset include/linux/sockptr.h:48 [inline] copy_from_sockptr include/linux/sockptr.h:61 [inline] do_sock_getsockopt+0x1d1/0x740 net/socket.c:2352 __sys_getsockopt net/socket.c:2393 [inline] __do_sys_getsockopt net/socket.c:2400 [inline] __se_sys_getsockopt net/socket.c:2397 [inline] __x64_sys_getsockopt+0x2a1/0x370 net/socket.c:2397 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __might_fault+0xc6/0x120 mm/memory.c:6851 _copy_from_iter+0x100/0x1c40 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+0x213d/0x5330 net/ipv4/tcp.c:1222 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1358 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:733 sock_write_iter+0x2d7/0x3f0 net/socket.c:1137 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xad1/0xd10 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (sk_lock-AF_INET){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 lock_sock_nested+0x48/0x100 net/core/sock.c:3662 lock_sock include/net/sock.h:1624 [inline] inet_shutdown+0x6d/0x390 net/ipv4/af_inet.c:905 nbd_mark_nsock_dead+0x2e3/0x560 drivers/block/nbd.c:318 sock_shutdown+0x165/0x280 drivers/block/nbd.c:411 nbd_start_device_ioctl drivers/block/nbd.c:1537 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0xac7/0xf40 drivers/block/nbd.c:1642 blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&nsock->tx_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 nbd_handle_cmd drivers/block/nbd.c:1140 [inline] nbd_queue_rq+0x262/0xef0 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0xad5/0x19d0 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+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354 blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917 __blk_flush_plug+0x420/0x500 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] __submit_bio+0x54a/0x6a0 block/blk-core.c:642 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446 filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2390 do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960 read_mapping_folio include/linux/pagemap.h:1023 [inline] read_part_sector+0xb3/0x260 block/partitions/core.c:722 adfspart_check_ICS+0xcb/0xa20 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+0x781/0x14d0 block/partitions/core.c:693 blkdev_get_whole+0x2d2/0x450 block/bdev.c:706 bdev_open+0x2d4/0xc50 block/bdev.c:915 blkdev_open+0x38e/0x4e0 block/fops.c:652 do_dentry_open+0xdee/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 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+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&cmd->lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 nbd_queue_rq+0xcf/0xef0 drivers/block/nbd.c:1196 blk_mq_dispatch_rq_list+0xad5/0x19d0 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+0xb8a/0x1840 block/blk-mq-sched.c:309 blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331 blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354 blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917 __blk_flush_plug+0x420/0x500 block/blk-core.c:1213 blk_finish_plug block/blk-core.c:1240 [inline] __submit_bio+0x54a/0x6a0 block/blk-core.c:642 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744 submit_bh fs/buffer.c:2819 [inline] block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446 filemap_read_folio+0x14a/0x3b0 mm/filemap.c:2390 do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3960 read_mapping_folio include/linux/pagemap.h:1023 [inline] read_part_sector+0xb3/0x260 block/partitions/core.c:722 adfspart_check_ICS+0xcb/0xa20 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+0x781/0x14d0 block/partitions/core.c:693 blkdev_get_whole+0x2d2/0x450 block/bdev.c:706 bdev_open+0x2d4/0xc50 block/bdev.c:915 blkdev_open+0x38e/0x4e0 block/fops.c:652 do_dentry_open+0xdee/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 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+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (set->srcu){.+.+}-{0:0}: lock_sync+0x18b/0x310 kernel/locking/lockdep.c:5899 srcu_lock_sync include/linux/srcu.h:176 [inline] __synchronize_srcu+0xb1/0x400 kernel/rcu/srcutree.c:1418 elevator_disable+0xd4/0x4e0 block/elevator.c:661 blk_mq_elv_switch_none block/blk-mq.c:4951 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] blk_mq_update_nr_hw_queues+0x5d3/0x1a30 block/blk-mq.c:5070 nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1476 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1642 blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->sysfs_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 blk_mq_elv_switch_none block/blk-mq.c:4937 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5018 [inline] blk_mq_update_nr_hw_queues+0x388/0x1a30 block/blk-mq.c:5070 nbd_start_device+0x163/0xab0 drivers/block/nbd.c:1476 nbd_start_device_ioctl drivers/block/nbd.c:1527 [inline] __nbd_ioctl drivers/block/nbd.c:1602 [inline] nbd_ioctl+0x5dc/0xf40 drivers/block/nbd.c:1642 blkdev_ioctl+0x5d2/0x6f0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&q->q_usage_counter(io)#53){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 bio_queue_enter block/blk.h:78 [inline] blk_mq_submit_bio+0x14e1/0x25d0 block/blk-mq.c:3091 __submit_bio+0x2cf/0x6a0 block/blk-core.c:628 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744 mpage_bio_submit_read fs/mpage.c:75 [inline] mpage_readahead+0x630/0x780 fs/mpage.c:377 read_pages+0x17b/0x570 mm/readahead.c:161 page_cache_ra_unbounded+0x708/0x820 mm/readahead.c:298 do_page_cache_ra mm/readahead.c:328 [inline] force_page_cache_ra mm/readahead.c:357 [inline] page_cache_sync_ra+0x3e2/0xb00 mm/readahead.c:585 filemap_get_pages+0x59a/0x1fb0 mm/filemap.c:2580 filemap_read+0x464/0x1260 mm/filemap.c:2691 blkdev_read_iter+0x31f/0x460 block/fops.c:796 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x977/0xb40 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 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)#53 --> &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)#53); *** DEADLOCK *** 1 lock held by udevd/17250: #0: ffff888148c4ce40 (mapping.invalidate_lock#2){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline] #0: ffff888148c4ce40 (mapping.invalidate_lock#2){.+.+}-{4:4}, at: page_cache_ra_unbounded+0x156/0x820 mm/readahead.c:229 stack backtrace: CPU: 0 UID: 0 PID: 17250 Comm: udevd Not tainted 6.14.0-rc4-syzkaller-00295-gb91872c56940 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 bio_queue_enter block/blk.h:78 [inline] blk_mq_submit_bio+0x14e1/0x25d0 block/blk-mq.c:3091 __submit_bio+0x2cf/0x6a0 block/blk-core.c:628 __submit_bio_noacct_mq block/blk-core.c:715 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744 mpage_bio_submit_read fs/mpage.c:75 [inline] mpage_readahead+0x630/0x780 fs/mpage.c:377 read_pages+0x17b/0x570 mm/readahead.c:161 page_cache_ra_unbounded+0x708/0x820 mm/readahead.c:298 do_page_cache_ra mm/readahead.c:328 [inline] force_page_cache_ra mm/readahead.c:357 [inline] page_cache_sync_ra+0x3e2/0xb00 mm/readahead.c:585 filemap_get_pages+0x59a/0x1fb0 mm/filemap.c:2580 filemap_read+0x464/0x1260 mm/filemap.c:2691 blkdev_read_iter+0x31f/0x460 block/fops.c:796 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x977/0xb40 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa171516b6a 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:00007fff7953ddf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000007ffff0000 RCX: 00007fa171516b6a RDX: 0000000000000040 RSI: 00005589f5193048 RDI: 0000000000000009 RBP: 0000000000000040 R08: 00005589f5193020 R09: 00007fa1715f1b60 R10: 0000000000000002 R11: 0000000000000246 R12: 00005589f5193020 R13: 00005589f5193038 R14: 00005589f519aa88 R15: 00005589f519aa30