device ip6gre0 entered promiscuous mode
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BUG: KMSAN: uninit-value in memcmp+0x117/0x180 lib/string.c:863
CPU: 0 PID: 17063 Comm: syz-executor3 Not tainted 4.19.0+ #77
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+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x1a2/0x2e0 mm/kmsan/kmsan.c:911
 __msan_warning+0x74/0xd0 mm/kmsan/kmsan_instr.c:415
 memcmp+0x117/0x180 lib/string.c:863
 dev_uc_add_excl+0x17c/0x780 net/core/dev_addr_lists.c:464
 ndo_dflt_fdb_add net/core/rtnetlink.c:3467 [inline]
 rtnl_fdb_add+0xecb/0x12a0 net/core/rtnetlink.c:3562
 rtnetlink_rcv_msg+0x1148/0x1540 net/core/rtnetlink.c:4730
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4748
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe68/0x1250 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457569
Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8ac6876c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8ac68776d4
R13: 00000000004c3b16 R14: 00000000004d5c08 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_internal_poison_shadow+0xc8/0x1e0 mm/kmsan/kmsan.c:177
 kmsan_kmalloc+0x98/0x110 mm/kmsan/kmsan_hooks.c:104
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:113
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2727 [inline]
 __kmalloc_node_track_caller+0xf62/0x14e0 mm/slub.c:4360
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x42b/0xeb0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:996 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline]
 netlink_sendmsg+0xc9e/0x1440 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe68/0x1250 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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