device ip6gre0 entered promiscuous mode
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BUG: KMSAN: uninit-value in memcmp+0x11d/0x180 lib/string.c:863
CPU: 1 PID: 8113 Comm: syz-executor6 Not tainted 4.18.0-rc8+ #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x17c/0x1c0 lib/dump_stack.c:113
 kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:982
 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:645
 memcmp+0x11d/0x180 lib/string.c:863
 dev_uc_add_excl+0x176/0x780 net/core/dev_addr_lists.c:464
 ndo_dflt_fdb_add net/core/rtnetlink.c:3413 [inline]
 rtnl_fdb_add+0x11e1/0x12a0 net/core/rtnetlink.c:3508
 rtnetlink_rcv_msg+0xa0b/0x1530 net/core/rtnetlink.c:4665
 netlink_rcv_skb+0x36e/0x5f0 net/netlink/af_netlink.c:2455
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4683
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x1492/0x1740 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x114c/0x1350 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:642 [inline]
 sock_sendmsg net/socket.c:652 [inline]
 ___sys_sendmsg+0xe32/0x1250 net/socket.c:2126
 __sys_sendmsg net/socket.c:2164 [inline]
 __do_sys_sendmsg net/socket.c:2173 [inline]
 __se_sys_sendmsg net/socket.c:2171 [inline]
 __x64_sys_sendmsg+0x32d/0x460 net/socket.c:2171
 do_syscall_64+0x15b/0x220 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f3f0b564c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3f0b5656d4 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d40b8 R14: 00000000004c8ad8 R15: 0000000000000001

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:181
 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:100
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2720 [inline]
 __kmalloc_node_track_caller+0xb4c/0x11d0 mm/slub.c:4353
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2ce/0x9b0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline]
 netlink_sendmsg+0x776/0x1350 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:642 [inline]
 sock_sendmsg net/socket.c:652 [inline]
 ___sys_sendmsg+0xe32/0x1250 net/socket.c:2126
 __sys_sendmsg net/socket.c:2164 [inline]
 __do_sys_sendmsg net/socket.c:2173 [inline]
 __se_sys_sendmsg net/socket.c:2171 [inline]
 __x64_sys_sendmsg+0x32d/0x460 net/socket.c:2171
 do_syscall_64+0x15b/0x220 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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