BUG: spinlock recursion on CPU#1, syz-executor.4/12551
 lock: 0xffff8880576a0778, .magic: dead4ead, .owner: syz-executor.4/12551, .owner_cpu: 1
CPU: 1 PID: 12551 Comm: syz-executor.4 Not tainted 4.14.215-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+0x1b2/0x283 lib/dump_stack.c:58
 debug_spin_lock_before kernel/locking/spinlock_debug.c:84 [inline]
 do_raw_spin_lock+0x1a2/0x200 kernel/locking/spinlock_debug.c:112
 netif_addr_lock_nested include/linux/netdevice.h:3699 [inline]
 dev_mc_sync+0x10b/0x1c0 net/core/dev_addr_lists.c:765
 vlan_dev_set_rx_mode+0x38/0x80 net/8021q/vlan_dev.c:486
 __dev_set_rx_mode+0x191/0x2a0 net/core/dev.c:6716
 dev_uc_unsync net/core/dev_addr_lists.c:600 [inline]
 dev_uc_unsync+0x16c/0x1c0 net/core/dev_addr_lists.c:592
 bond_hw_addr_flush drivers/net/bonding/bond_main.c:559 [inline]
 bond_enslave+0x1dac/0x4cc0 drivers/net/bonding/bond_main.c:1805
 do_set_master+0x19e/0x200 net/core/rtnetlink.c:1961
 rtnl_newlink+0x134c/0x1830 net/core/rtnetlink.c:2757
 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
RIP: 0033:0x45e219
RSP: 002b:00007f74fb12bc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000000040000 RSI: 0000000020000300 RDI: 000000000000000a
RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffccaa4de8f R14: 00007f74fb12c9c0 R15: 000000000119bf8c
L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.