=====================================================
BUG: KMSAN: uninit-value in ip_check_mc_rcu+0x340/0x7f0 net/ipv4/igmp.c:2707
CPU: 1 PID: 18047 Comm: syz-executor.1 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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:122
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:201
 ip_check_mc_rcu+0x340/0x7f0 net/ipv4/igmp.c:2707
 ip_route_input_rcu+0x29c/0x63c0 net/ipv4/route.c:2331
 ip_route_input_noref+0x123/0x160 net/ipv4/route.c:2302
 ip_rcv_finish_core+0x8e8/0x2160 net/ipv4/ip_input.c:353
 ip_rcv_finish net/ipv4/ip_input.c:426 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_rcv+0x4f7/0x830 net/ipv4/ip_input.c:539
 __netif_receive_skb_one_core net/core/dev.c:5286 [inline]
 __netif_receive_skb+0x1ec/0x640 net/core/dev.c:5400
 process_backlog+0x523/0xc10 net/core/dev.c:6242
 napi_poll+0x4aa/0x1090 net/core/dev.c:6688
 net_rx_action+0x35c/0xd40 net/core/dev.c:6758
 __do_softirq+0x1b9/0x7ed kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x6e/0x90 arch/x86/kernel/irq_64.c:77
 do_softirq kernel/softirq.c:343 [inline]
 __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:195
 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline]
 __dev_queue_xmit+0x3993/0x4490 net/core/dev.c:4163
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4169
 __bpf_tx_skb net/core/filter.c:2112 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2137 [inline]
 __bpf_redirect+0x889/0x1690 net/core/filter.c:2160
 ____bpf_clone_redirect net/core/filter.c:2191 [inline]
 bpf_clone_redirect+0x498/0x650 net/core/filter.c:2163
 ___bpf_prog_run+0x4256/0x93c0 kernel/bpf/core.c:1516
 __bpf_prog_run512+0x12e/0x190 kernel/bpf/core.c:1694
 bpf_test_run+0x557/0xe30 include/linux/filter.h:734
 bpf_prog_test_run_skb+0x17d7/0x3450 net/bpf/test_run.c:496
 bpf_prog_test_run kernel/bpf/syscall.c:2996 [inline]
 __do_sys_bpf+0xb79a/0x1a8a0 kernel/bpf/syscall.c:4196
 __se_sys_bpf+0x8e/0xa0 kernel/bpf/syscall.c:4136
 __ia32_sys_bpf+0x4a/0x70 kernel/bpf/syscall.c:4136
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f84549
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f557e0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020000080
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:129 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:297
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:234
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:254
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:114
 pskb_expand_head+0x3eb/0x1df0 net/core/skbuff.c:1638
 skb_ensure_writable+0x4d1/0x590 net/core/skbuff.c:5458
 sctp_error net/netfilter/nf_conntrack_proto_sctp.c:341 [inline]
 nf_conntrack_sctp_packet+0x1247/0x41e0 net/netfilter/nf_conntrack_proto_sctp.c:376
 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1775 [inline]
 nf_conntrack_in+0x14d6/0x2af3 net/netfilter/nf_conntrack_core.c:1851
 ipv4_conntrack_in+0x68/0x80 net/netfilter/nf_conntrack_proto.c:178
 nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline]
 nf_hook_slow+0x17b/0x460 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:256 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x7a3/0x830 net/ipv4/ip_input.c:539
 __netif_receive_skb_one_core net/core/dev.c:5286 [inline]
 __netif_receive_skb+0x1ec/0x640 net/core/dev.c:5400
 process_backlog+0x523/0xc10 net/core/dev.c:6242
 napi_poll+0x4aa/0x1090 net/core/dev.c:6688
 net_rx_action+0x35c/0xd40 net/core/dev.c:6758
 __do_softirq+0x1b9/0x7ed kernel/softirq.c:298

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:129 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:297
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:234
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:254
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:114
 pskb_expand_head+0x3eb/0x1df0 net/core/skbuff.c:1638
 __skb_cow include/linux/skbuff.h:3160 [inline]
 skb_cow_head include/linux/skbuff.h:3194 [inline]
 ip_tunnel_xmit+0x2f9d/0x3a40 net/ipv4/ip_tunnel.c:809
 __gre_xmit net/ipv4/ip_gre.c:466 [inline]
 ipgre_xmit+0x1261/0x1380 net/ipv4/ip_gre.c:650
 __netdev_start_xmit include/linux/netdevice.h:4636 [inline]
 netdev_start_xmit include/linux/netdevice.h:4650 [inline]
 xmit_one+0x1fc/0x760 net/core/dev.c:3561
 dev_hard_start_xmit net/core/dev.c:3577 [inline]
 __dev_queue_xmit+0x3310/0x4490 net/core/dev.c:4136
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4169
 __bpf_tx_skb net/core/filter.c:2112 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2137 [inline]
 __bpf_redirect+0x889/0x1690 net/core/filter.c:2160
 ____bpf_clone_redirect net/core/filter.c:2191 [inline]
 bpf_clone_redirect+0x498/0x650 net/core/filter.c:2163
 ___bpf_prog_run+0x4256/0x93c0 kernel/bpf/core.c:1516
 __bpf_prog_run512+0x12e/0x190 kernel/bpf/core.c:1694
 bpf_test_run+0x557/0xe30 include/linux/filter.h:734
 bpf_prog_test_run_skb+0x17d7/0x3450 net/bpf/test_run.c:496
 bpf_prog_test_run kernel/bpf/syscall.c:2996 [inline]
 __do_sys_bpf+0xb79a/0x1a8a0 kernel/bpf/syscall.c:4196
 __se_sys_bpf+0x8e/0xa0 kernel/bpf/syscall.c:4136
 __ia32_sys_bpf+0x4a/0x70 kernel/bpf/syscall.c:4136
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:129 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:112
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2903 [inline]
 __kmalloc_node_track_caller+0x7de/0x1320 mm/slub.c:4507
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 pskb_expand_head+0x25f/0x1df0 net/core/skbuff.c:1629
 __skb_cow include/linux/skbuff.h:3160 [inline]
 skb_cow_head include/linux/skbuff.h:3194 [inline]
 ipgre_xmit+0x84b/0x1380 net/ipv4/ip_gre.c:629
 __netdev_start_xmit include/linux/netdevice.h:4636 [inline]
 netdev_start_xmit include/linux/netdevice.h:4650 [inline]
 xmit_one+0x1fc/0x760 net/core/dev.c:3561
 dev_hard_start_xmit net/core/dev.c:3577 [inline]
 __dev_queue_xmit+0x3310/0x4490 net/core/dev.c:4136
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4169
 __bpf_tx_skb net/core/filter.c:2112 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2137 [inline]
 __bpf_redirect+0x889/0x1690 net/core/filter.c:2160
 ____bpf_clone_redirect net/core/filter.c:2191 [inline]
 bpf_clone_redirect+0x498/0x650 net/core/filter.c:2163
 ___bpf_prog_run+0x4256/0x93c0 kernel/bpf/core.c:1516
 __bpf_prog_run512+0x12e/0x190 kernel/bpf/core.c:1694
 bpf_test_run+0x557/0xe30 include/linux/filter.h:734
 bpf_prog_test_run_skb+0x17d7/0x3450 net/bpf/test_run.c:496
 bpf_prog_test_run kernel/bpf/syscall.c:2996 [inline]
 __do_sys_bpf+0xb79a/0x1a8a0 kernel/bpf/syscall.c:4196
 __se_sys_bpf+0x8e/0xa0 kernel/bpf/syscall.c:4136
 __ia32_sys_bpf+0x4a/0x70 kernel/bpf/syscall.c:4136
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
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