IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready ====================================================== WARNING: possible circular locking dependency detected 4.14.225-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/18244 is trying to acquire lock: (&xt[i].mutex){+.+.}, at: [] xt_find_revision+0x88/0x200 net/netfilter/x_tables.c:373 but task is already holding lock: (&table[i].mutex){+.+.}, at: [] nfnl_lock net/netfilter/nfnetlink.c:61 [inline] (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&table[i].mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93 call_netdevice_notifiers_info net/core/dev.c:1667 [inline] call_netdevice_notifiers net/core/dev.c:1683 [inline] rollback_registered_many+0x765/0xba0 net/core/dev.c:7203 unregister_netdevice_many.part.0+0x18/0x2e0 net/core/dev.c:8285 unregister_netdevice_many+0x36/0x50 net/core/dev.c:8284 rtnl_delete_link net/core/rtnetlink.c:2375 [inline] rtnl_dellink+0x25b/0x6a0 net/core/rtnetlink.c:2411 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (rtnl_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1630 tee_tg_destroy+0x5c/0xb0 net/netfilter/xt_TEE.c:123 cleanup_entry+0x232/0x310 net/ipv6/netfilter/ip6_tables.c:684 __do_replace+0x38d/0x580 net/ipv6/netfilter/ip6_tables.c:1105 do_replace net/ipv6/netfilter/ip6_tables.c:1161 [inline] do_ip6t_set_ctl+0x256/0x3b0 net/ipv6/netfilter/ip6_tables.c:1685 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt+0xc0/0x120 net/ipv6/ipv6_sockglue.c:937 tcp_setsockopt+0x7b/0xc0 net/ipv4/tcp.c:2828 SYSC_setsockopt net/socket.c:1865 [inline] SyS_setsockopt+0x110/0x1e0 net/socket.c:1844 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&xt[i].mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 xt_find_revision+0x88/0x200 net/netfilter/x_tables.c:373 nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678 nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: &xt[i].mutex --> rtnl_mutex --> &table[i].mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&table[i].mutex); lock(rtnl_mutex); lock(&table[i].mutex); lock(&xt[i].mutex); *** DEADLOCK *** 1 lock held by syz-executor.1/18244: #0: (&table[i].mutex){+.+.}, at: [] nfnl_lock net/netfilter/nfnetlink.c:61 [inline] #0: (&table[i].mutex){+.+.}, at: [] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209 stack backtrace: CPU: 0 PID: 18244 Comm: syz-executor.1 Not tainted 4.14.225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 xt_find_revision+0x88/0x200 net/netfilter/x_tables.c:373 nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678 nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465f69 RSP: 002b:00007ff353713188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff5a2b4fbf R14: 00007ff353713300 R15: 0000000000022000 IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. overlayfs: unrecognized mount option "nfs_export=nff" or missing value overlayfs: unrecognized mount option "nfs_export=nff" or missing value print_req_error: I/O error, dev loop0, sector 0 overlayfs: unrecognized mount option "nfs_export=nff" or missing value overlayfs: unrecognized mount option "nfs_export=nff" or missing value overlayfs: unrecognized mount option "nfs_export=nff" or missing value 9pnet: p9_fd_create_unix (18612): problem connecting socket: éq‰Y’3aK: -111 9pnet: p9_fd_create_unix (18618): problem connecting socket: éq‰Y’3aK: -111 9pnet: p9_fd_create_unix (18636): problem connecting socket: éq‰Y’3aK: -111 9pnet: p9_fd_create_unix (18645): problem connecting socket: éq‰Y’3aK: -91 9pnet: p9_fd_create_unix (18654): problem connecting socket: éq‰Y’3aK: -111 9pnet: p9_fd_create_unix (18669): problem connecting socket: éq‰Y’3aK: -111 9pnet: p9_fd_create_unix (18672): problem connecting socket: éq‰Y’3aK: -91 9pnet: p9_fd_create_unix (18692): problem connecting socket: éq‰Y’3aK: -91 new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored audit: type=1400 audit(1615474896.631:179): apparmor="DENIED" operation="change_hat" info="unconfined can not change_hat" error=-1 profile="unconfined" pid=18766 comm="syz-executor.3" new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored audit: type=1400 audit(1615474896.771:180): apparmor="DENIED" operation="change_hat" info="unconfined can not change_hat" error=-1 profile="unconfined" pid=18790 comm="syz-executor.3" audit: type=1400 audit(1615474896.871:181): apparmor="DENIED" operation="change_hat" info="unconfined can not change_hat" error=-1 profile="unconfined" pid=18805 comm="syz-executor.3" new mount options do not match the existing superblock, will be ignored new mount options do not match the existing superblock, will be ignored audit: type=1400 audit(1615474896.981:182): apparmor="DENIED" operation="change_hat" info="unconfined can not change_hat" error=-1 profile="unconfined" pid=18818 comm="syz-executor.3" Bluetooth: hci0 command 0x0401 tx timeout syz-executor.3 (18896): drop_caches: 1 syz-executor.3 (18932): drop_caches: 1 syz-executor.3 (18947): drop_caches: 1 squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop1 squashfs: SQUASHFS error: Can't find a SQUASHFS superblock on loop1