syzbot

Enabling of bearer <udp:syz2> rejected, already enabled
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BUG: KMSAN: uninit-value in __skb_dst_copy include/net/dst.h:290 [inline]
BUG: KMSAN: uninit-value in skb_dst_copy include/net/dst.h:296 [inline]
BUG: KMSAN: uninit-value in __copy_skb_header+0x292/0x760 net/core/skbuff.c:798
CPU: 1 PID: 21681 Comm: syz-executor1 Not tainted 4.20.0-rc7+ #2
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+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:295
 __skb_dst_copy include/net/dst.h:290 [inline]
 skb_dst_copy include/net/dst.h:296 [inline]
 __copy_skb_header+0x292/0x760 net/core/skbuff.c:798
 __skb_clone+0xa2/0x990 net/core/skbuff.c:852
 skb_clone+0x3e8/0x580 net/core/skbuff.c:1287
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:296 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x7b3/0xec0 net/netlink/af_netlink.c:334
 __netlink_sendskb net/netlink/af_netlink.c:1254 [inline]
 netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
 netlink_unicast+0x9cd/0x1020 net/netlink/af_netlink.c:1351
 netlink_ack+0x1052/0x1110 net/netlink/af_netlink.c:2447
 netlink_rcv_skb+0x31d/0x640 net/netlink/af_netlink.c:2483
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:637
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0xf40/0x1020 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 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+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd71c8c6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9
RDX: 0000000000000000 RSI: 0000000020000a40 RDI: 0000000000000006
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd71c8c76d4
R13: 00000000004c4fac R14: 00000000004d87e8 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmem_cache_alloc+0x572/0xb90 mm/slub.c:2777
 skb_clone+0x300/0x580 net/core/skbuff.c:1280
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:296 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x7b3/0xec0 net/netlink/af_netlink.c:334
 __netlink_sendskb net/netlink/af_netlink.c:1254 [inline]
 netlink_sendskb net/netlink/af_netlink.c:1263 [inline]
 netlink_unicast+0x9cd/0x1020 net/netlink/af_netlink.c:1351
 netlink_ack+0x1052/0x1110 net/netlink/af_netlink.c:2447
 netlink_rcv_skb+0x31d/0x640 net/netlink/af_netlink.c:2483
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:637
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0xf40/0x1020 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xdb9/0x11b0 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+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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