syzbot

IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
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BUG: KMSAN: uninit-value in sk_filter_trim_cap+0x828/0xcc0 net/core/filter.c:121
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.7.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 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
 sk_filter_trim_cap+0x828/0xcc0 net/core/filter.c:121
 sk_filter include/linux/filter.h:833 [inline]
 sock_queue_rcv_skb+0x83/0x130 net/core/sock.c:487
 packet_rcv_spkt+0x656/0x7c0 net/packet/af_packet.c:1851
 dev_queue_xmit_nit+0x1199/0x1270 net/core/dev.c:2276
 xmit_one net/core/dev.c:3473 [inline]
 dev_hard_start_xmit+0x20f/0xab0 net/core/dev.c:3493
 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4052
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4085
 neigh_resolve_output+0xab0/0xb40 net/core/neighbour.c:1489
 neigh_output include/net/neighbour.h:510 [inline]
 ip6_finish_output2+0x20fd/0x2640 net/ipv6/ip6_output.c:117
 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0x1047/0x15a0 net/ipv6/ndisc.c:506
 ndisc_send_ns+0xe38/0xe80 net/ipv6/ndisc.c:648
 addrconf_dad_work+0xc2e/0x2ac0 net/ipv6/addrconf.c:4131
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2268
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2414
 kthread+0x4b5/0x4f0 kernel/kthread.c:269
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 __bpf_prog_run_save_cb include/linux/filter.h:693 [inline]
 bpf_prog_run_save_cb include/linux/filter.h:707 [inline]
 sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119
 sk_filter include/linux/filter.h:833 [inline]
 sock_queue_rcv_skb+0x83/0x130 net/core/sock.c:487
 packet_rcv_spkt+0x656/0x7c0 net/packet/af_packet.c:1851
 dev_queue_xmit_nit+0x1199/0x1270 net/core/dev.c:2276
 xmit_one net/core/dev.c:3473 [inline]
 dev_hard_start_xmit+0x20f/0xab0 net/core/dev.c:3493
 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4052
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4085
 neigh_resolve_output+0xab0/0xb40 net/core/neighbour.c:1489
 neigh_output include/net/neighbour.h:510 [inline]
 ip6_finish_output2+0x20fd/0x2640 net/ipv6/ip6_output.c:117
 __ip6_finish_output+0x824/0x8e0 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0x1047/0x15a0 net/ipv6/ndisc.c:506
 ndisc_send_ns+0xe38/0xe80 net/ipv6/ndisc.c:648
 addrconf_dad_work+0xc2e/0x2ac0 net/ipv6/addrconf.c:4131
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2268
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2414
 kthread+0x4b5/0x4f0 kernel/kthread.c:269
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353

Local variable ----regs@__bpf_prog_run32 created at:
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
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