Buffer I/O error on dev nbd0, logical block 1, async page read ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ udevd/11871 is trying to acquire lock: ffff888143713b88 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: __submit_bio+0x207/0x5a0 block/blk-core.c:637 but task is already holding lock: ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2497 [inline] ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x8d7/0x1de0 mm/filemap.c:2661 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (mapping.invalidate_lock){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1 filemap_fault+0x6b9/0x12b0 mm/filemap.c:3489 __do_fault+0x138/0x390 mm/memory.c:5280 do_read_fault mm/memory.c:5698 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing mm/memory.c:4361 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x35e3/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68 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:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] _copy_from_iter+0x24f/0x1790 lib/iov_iter.c:260 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:2269 [inline] skb_copy_to_page_nocache include/net/sock.h:2295 [inline] tcp_sendmsg_locked+0x2347/0x5540 net/ipv4/tcp.c:1272 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1413 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x19c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (sk_lock-AF_INET){+.+.}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 lock_sock_nested+0x48/0x100 net/core/sock.c:3720 lock_sock include/net/sock.h:1679 [inline] inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:907 nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318 sock_shutdown+0x15e/0x260 drivers/block/nbd.c:411 nbd_clear_sock drivers/block/nbd.c:1424 [inline] nbd_config_put+0x342/0x790 drivers/block/nbd.c:1448 nbd_release+0xfe/0x140 drivers/block/nbd.c:1753 bdev_release+0x536/0x650 block/bdev.c:-1 blkdev_release+0x15/0x20 block/fops.c:702 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&nsock->tx_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 nbd_handle_cmd drivers/block/nbd.c:1140 [inline] nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024 read_mapping_folio include/linux/pagemap.h:999 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 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+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&cmd->lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024 read_mapping_folio include/linux/pagemap.h:999 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 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+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (set->srcu){.+.+}-{0:0}: lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916 srcu_lock_sync include/linux/srcu.h:173 [inline] __synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1439 elevator_switch+0x12b/0x640 block/elevator.c:588 elevator_change+0x315/0x4c0 block/elevator.c:691 elevator_set_default+0x186/0x260 block/elevator.c:767 blk_register_queue+0x34e/0x3f0 block/blk-sysfs.c:942 __add_disk+0x677/0xd50 block/genhd.c:528 add_disk_fwnode+0xfc/0x480 block/genhd.c:597 add_disk include/linux/blkdev.h:775 [inline] nbd_dev_add+0x717/0xae0 drivers/block/nbd.c:1981 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2688 do_one_initcall+0x236/0x820 init/main.c:1283 do_initcall_level+0x104/0x190 init/main.c:1345 do_initcalls+0x59/0xa0 init/main.c:1361 kernel_init_freeable+0x334/0x4b0 init/main.c:1593 kernel_init+0x1d/0x1d0 init/main.c:1483 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (&q->elevator_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 elevator_change+0x1e5/0x4c0 block/elevator.c:689 elevator_set_none+0x42/0xb0 block/elevator.c:782 blk_mq_elv_switch_none block/blk-mq.c:5032 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5075 [inline] blk_mq_update_nr_hw_queues+0x598/0x1ab0 block/blk-mq.c:5133 nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1486 nbd_genl_connect+0x135b/0x18f0 drivers/block/nbd.c:2236 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&q->q_usage_counter(io)#49){++++}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 bio_queue_enter block/blk.h:90 [inline] blk_mq_submit_bio+0xb60/0x25b0 block/blk-mq.c:3153 __submit_bio+0x207/0x5a0 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 filemap_update_page mm/filemap.c:2531 [inline] filemap_get_pages+0x1690/0x1de0 mm/filemap.c:2661 filemap_read+0x3f6/0x11a0 mm/filemap.c:2748 blkdev_read_iter+0x30a/0x440 block/fops.c:852 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x55a/0xa30 fs/read_write.c:572 ksys_read+0x145/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &q->q_usage_counter(io)#49 --> sk_lock-AF_INET --> mapping.invalidate_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(mapping.invalidate_lock); lock(sk_lock-AF_INET); lock(mapping.invalidate_lock); rlock(&q->q_usage_counter(io)#49); *** DEADLOCK *** 2 locks held by udevd/11871: #0: ffff888148c59ea8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff888148c59ea8 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:851 #1: ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline] #1: ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2497 [inline] #1: ffff888148c5a048 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x8d7/0x1de0 mm/filemap.c:2661 stack backtrace: CPU: 1 UID: 0 PID: 11871 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 bio_queue_enter block/blk.h:90 [inline] blk_mq_submit_bio+0xb60/0x25b0 block/blk-mq.c:3153 __submit_bio+0x207/0x5a0 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 filemap_update_page mm/filemap.c:2531 [inline] filemap_get_pages+0x1690/0x1de0 mm/filemap.c:2661 filemap_read+0x3f6/0x11a0 mm/filemap.c:2748 blkdev_read_iter+0x30a/0x440 block/fops.c:852 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x55a/0xa30 fs/read_write.c:572 ksys_read+0x145/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ab73d7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd12d0b7f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f4ab734b880 RCX: 00007f4ab73d7407 RDX: 0000000000000200 RSI: 00007f4ab734a000 RDI: 0000000000000009 RBP: 0000561ace391050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000561ace38aa48 R15: 00007f4ab75f039c