syzbot

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BUG: KMSAN: uninit-value in netlink_policy_dump_start+0x137d/0x1520 net/netlink/policy.c:103
CPU: 0 PID: 8467 Comm: syz-executor169 Not tainted 5.8.0-rc5-syzkaller #0
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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 netlink_policy_dump_start+0x137d/0x1520 net/netlink/policy.c:103
 ctrl_dumppolicy+0x201/0x1610 net/netlink/genetlink.c:1078
 genl_lock_dumpit+0xdb/0x150 net/netlink/genetlink.c:553
 netlink_dump+0xb73/0x1cb0 net/netlink/af_netlink.c:2245
 __netlink_dump_start+0xcf2/0xea0 net/netlink/af_netlink.c:2353
 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:616 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:711 [inline]
 genl_rcv_msg+0x1245/0x18a0 net/netlink/genetlink.c:731
 netlink_rcv_skb+0x6d7/0x7e0 net/netlink/af_netlink.c:2469
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:742
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x11c8/0x1490 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x173a/0x1840 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0xc82/0x1240 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmsg+0x6d1/0x840 net/socket.c:2439
 __do_sys_sendmsg net/socket.c:2448 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2446
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4402a9
Code: Bad RIP value.
RSP: 002b:00007fffa766bf88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402a9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401ab0
R13: 0000000000401b40 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2839 [inline]
 slab_alloc mm/slub.c:2848 [inline]
 __kmalloc_track_caller+0xbe8/0xe10 mm/slub.c:4447
 __do_krealloc mm/slab_common.c:1673 [inline]
 krealloc+0x21d/0x410 mm/slab_common.c:1702
 add_policy net/netlink/policy.c:49 [inline]
 netlink_policy_dump_start+0x111c/0x1520 net/netlink/policy.c:117
 ctrl_dumppolicy+0x201/0x1610 net/netlink/genetlink.c:1078
 genl_lock_dumpit+0xdb/0x150 net/netlink/genetlink.c:553
 netlink_dump+0xb73/0x1cb0 net/netlink/af_netlink.c:2245
 __netlink_dump_start+0xcf2/0xea0 net/netlink/af_netlink.c:2353
 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:616 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:711 [inline]
 genl_rcv_msg+0x1245/0x18a0 net/netlink/genetlink.c:731
 netlink_rcv_skb+0x6d7/0x7e0 net/netlink/af_netlink.c:2469
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:742
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x11c8/0x1490 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x173a/0x1840 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0xc82/0x1240 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmsg+0x6d1/0x840 net/socket.c:2439
 __do_sys_sendmsg net/socket.c:2448 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2446
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2446
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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