netlink: 4 bytes leftover after parsing attributes in process `syz-executor681'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor681'. nbd: socks must be embedded in a SOCK_ITEM attr ====================================================== WARNING: possible circular locking dependency detected 5.13.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor681/8428 is trying to acquire lock: ffff88801f110d18 (&disk->open_mutex){+.+.}-{3:3}, at: del_gendisk+0x86/0x610 block/genhd.c:587 but task is already holding lock: ffffffff8d67c148 (nbd_index_mutex){+.+.}-{3:3}, at: refcount_dec_and_mutex_lock+0x2e/0x100 lib/refcount.c:118 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (nbd_index_mutex){+.+.}-{3:3}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1ad/0x3770 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 nbd_open+0x84/0xb10 drivers/block/nbd.c:1456 blkdev_get_whole+0x94/0x500 fs/block_dev.c:1251 blkdev_get_by_dev+0x339/0xdc0 fs/block_dev.c:1415 blkdev_open+0x132/0x2c0 fs/block_dev.c:1510 do_dentry_open+0x7cb/0x1010 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x28e6/0x39b0 fs/namei.c:3494 do_filp_open+0x221/0x460 fs/namei.c:3521 do_sys_openat2+0x124/0x460 fs/open.c:1195 do_sys_open fs/open.c:1211 [inline] __do_sys_open fs/open.c:1219 [inline] __se_sys_open fs/open.c:1215 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1215 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&disk->open_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1ad/0x3770 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 del_gendisk+0x86/0x610 block/genhd.c:587 nbd_dev_remove drivers/block/nbd.c:224 [inline] nbd_put+0x8d/0x170 drivers/block/nbd.c:246 nbd_genl_connect+0x17e7/0x1aa0 drivers/block/nbd.c:1957 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0xfb4/0x13c0 net/netlink/genetlink.c:800 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg net/socket.c:722 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2385 ___sys_sendmsg net/socket.c:2439 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2468 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(nbd_index_mutex); lock(&disk->open_mutex); lock(nbd_index_mutex); lock(&disk->open_mutex); *** DEADLOCK *** 3 locks held by syz-executor681/8428: #0: ffffffff8df97230 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:810 #1: ffffffff8df970e8 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8df970e8 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x125/0x13c0 net/netlink/genetlink.c:798 #2: ffffffff8d67c148 (nbd_index_mutex){+.+.}-{3:3}, at: refcount_dec_and_mutex_lock+0x2e/0x100 lib/refcount.c:118 stack backtrace: CPU: 0 PID: 8428 Comm: syz-executor681 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:96 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2009 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __mutex_lock_common+0x1ad/0x3770 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 del_gendisk+0x86/0x610 block/genhd.c:587 nbd_dev_remove drivers/block/nbd.c:224 [inline] nbd_put+0x8d/0x170 drivers/block/nbd.c:246 nbd_genl_connect+0x17e7/0x1aa0 drivers/block/nbd.c:1957 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0xfb4/0x13c0 net/netlink/genetlink.c:800 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg net/socket.c:722 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2385 ___sys_sendmsg net/socket.c:2439 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2468 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43fa29 Code: 28 c3 e8 5a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdf3000888 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 000000000043fa29 RDX: 0000000000000000 RSI: 0000000020000b40 RDI: 0000000000000003 RBP: 0000000000403490 R08: 0000000000000000 R09: 00000000004004a0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403520 R13: 0000000000000000 R14: 00000000004ad018 R15: 00000000004004a0 general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 8428 Comm: syz-executor681 Not tainted 5.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:blk_mq_map_queue_type block/blk-mq.h:96 [inline] RIP: 0010:blk_mq_get_sq_hctx block/blk-mq.c:1663 [inline] RIP: 0010:blk_mq_run_hw_queues+0x14f/0x430 block/blk-mq.c:1682 Code: 80 3c 08 00 74 08 48 89 ef e8 0d 0f dd fd 44 89 fb 48 c1 e3 02 48 03 5d 00 48 89 d8 48 c1 e8 03 48 bd 00 00 00 00 00 fc ff df <8a> 04 28 84 c0 0f 85 b7 02 00 00 8b 03 49 8d 1c c4 48 89 d8 48 c1 RSP: 0018:ffffc90000f4f160 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f9f8048 RBP: dffffc0000000000 R08: ffffffff83eb6412 R09: ffffed1003f3f129 R10: ffffed1003f3f129 R11: 0000000000000000 R12: ffff8881462fcbb8 R13: 0000000000000000 R14: ffff88801f9f8000 R15: 0000000000000000 FS: 00000000023b3300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055dc6ea4a928 CR3: 0000000028108000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: blk_set_queue_dying block/blk-core.c:353 [inline] blk_cleanup_queue+0x9c/0x220 block/blk-core.c:380 blk_cleanup_disk+0x3b/0x80 block/genhd.c:1324 nbd_dev_remove drivers/block/nbd.c:226 [inline] nbd_put+0x9d/0x170 drivers/block/nbd.c:246 nbd_genl_connect+0x17e7/0x1aa0 drivers/block/nbd.c:1957 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0xfb4/0x13c0 net/netlink/genetlink.c:800 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg net/socket.c:722 [inline] ____sys_sendmsg+0x5a2/0x900 net/socket.c:2385 ___sys_sendmsg net/socket.c:2439 [inline] __sys_sendmsg+0x319/0x400 net/socket.c:2468 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x43fa29 Code: 28 c3 e8 5a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdf3000888 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 000000000043fa29 RDX: 0000000000000000 RSI: 0000000020000b40 RDI: 0000000000000003 RBP: 0000000000403490 R08: 0000000000000000 R09: 00000000004004a0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403520 R13: 0000000000000000 R14: 00000000004ad018 R15: 00000000004004a0 Modules linked in: ---[ end trace cbb5754f3f0ff674 ]--- RIP: 0010:blk_mq_map_queue_type block/blk-mq.h:96 [inline] RIP: 0010:blk_mq_get_sq_hctx block/blk-mq.c:1663 [inline] RIP: 0010:blk_mq_run_hw_queues+0x14f/0x430 block/blk-mq.c:1682 Code: 80 3c 08 00 74 08 48 89 ef e8 0d 0f dd fd 44 89 fb 48 c1 e3 02 48 03 5d 00 48 89 d8 48 c1 e8 03 48 bd 00 00 00 00 00 fc ff df <8a> 04 28 84 c0 0f 85 b7 02 00 00 8b 03 49 8d 1c c4 48 89 d8 48 c1 RSP: 0018:ffffc90000f4f160 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801f9f8048 RBP: dffffc0000000000 R08: ffffffff83eb6412 R09: ffffed1003f3f129 R10: ffffed1003f3f129 R11: 0000000000000000 R12: ffff8881462fcbb8 R13: 0000000000000000 R14: ffff88801f9f8000 R15: 0000000000000000 FS: 00000000023b3300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcea2a53000 CR3: 0000000028108000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400