===================================================== BUG: KMSAN: uninit-value in ____bpf_skb_get_nlattr net/core/filter.c:144 [inline] BUG: KMSAN: uninit-value in bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134 CPU: 1 PID: 16589 Comm: syz-executor.2 Not tainted 5.7.0-rc4-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+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 ____bpf_skb_get_nlattr net/core/filter.c:144 [inline] bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134 ___bpf_prog_run+0x214d/0x97a0 kernel/bpf/core.c:1516 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:599 [inline] bpf_prog_run_clear_cb include/linux/filter.h:721 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085 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_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x2056/0x2640 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] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb net/ipv6/ip6_output.c:1865 [inline] ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1885 icmpv6_push_pending_frames+0x674/0x6b0 net/ipv6/icmp.c:304 icmp6_send+0x32a3/0x39d0 net/ipv6/icmp.c:617 icmpv6_send+0xe4/0x110 net/ipv6/ip6_icmp.c:43 __udp6_lib_rcv+0x2a7c/0x4080 net/ipv6/udp.c:928 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1017 ip6_protocol_deliver_rcu+0x14d6/0x22c0 net/ipv6/ip6_input.c:433 ip6_input_finish net/ipv6/ip6_input.c:474 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:441 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core net/core/dev.c:5188 [inline] __netif_receive_skb net/core/dev.c:5302 [inline] process_backlog+0xa41/0x1410 net/core/dev.c:6134 napi_poll net/core/dev.c:6572 [inline] net_rx_action+0x786/0x1aa0 net/core/dev.c:6640 __do_softirq+0x311/0x83d kernel/softirq.c:293 do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1091 do_softirq kernel/softirq.c:338 [inline] __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:190 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:690 [inline] ip6_finish_output2+0x2113/0x2640 net/ipv6/ip6_output.c:118 __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] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb+0xfa/0x390 net/ipv6/ip6_output.c:1865 udp_v6_send_skb+0x1834/0x1e80 net/ipv6/udp.c:1175 udp_v6_push_pending_frames net/ipv6/udp.c:1208 [inline] udpv6_sendmsg+0x1d6d/0x4940 net/ipv6/udp.c:1500 inet6_sendmsg+0x276/0x2e0 net/ipv6/af_inet6.c:577 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0xc27/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmmsg+0x5fe/0xd60 net/socket.c:2506 __do_sys_sendmmsg net/socket.c:2535 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2532 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2532 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ca29 Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5bdae4bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004fc640 RCX: 000000000045ca29 RDX: 0000000000000004 RSI: 0000000020001ec0 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008e0 R14: 00000000004cba43 R15: 00007f5bdae4c6d4 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+0x6cbe/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_pin_on_cpu include/linux/filter.h:599 [inline] bpf_prog_run_clear_cb include/linux/filter.h:721 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085 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_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x2056/0x2640 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] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb net/ipv6/ip6_output.c:1865 [inline] ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1885 icmpv6_push_pending_frames+0x674/0x6b0 net/ipv6/icmp.c:304 icmp6_send+0x32a3/0x39d0 net/ipv6/icmp.c:617 icmpv6_send+0xe4/0x110 net/ipv6/ip6_icmp.c:43 __udp6_lib_rcv+0x2a7c/0x4080 net/ipv6/udp.c:928 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1017 ip6_protocol_deliver_rcu+0x14d6/0x22c0 net/ipv6/ip6_input.c:433 ip6_input_finish net/ipv6/ip6_input.c:474 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:441 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core net/core/dev.c:5188 [inline] __netif_receive_skb net/core/dev.c:5302 [inline] process_backlog+0xa41/0x1410 net/core/dev.c:6134 napi_poll net/core/dev.c:6572 [inline] net_rx_action+0x786/0x1aa0 net/core/dev.c:6640 __do_softirq+0x311/0x83d kernel/softirq.c:293 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_pin_on_cpu include/linux/filter.h:599 [inline] bpf_prog_run_clear_cb include/linux/filter.h:721 [inline] run_filter net/packet/af_packet.c:2012 [inline] packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085 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_hh_output include/net/neighbour.h:499 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x2056/0x2640 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] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb net/ipv6/ip6_output.c:1865 [inline] ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1885 icmpv6_push_pending_frames+0x674/0x6b0 net/ipv6/icmp.c:304 icmp6_send+0x32a3/0x39d0 net/ipv6/icmp.c:617 icmpv6_send+0xe4/0x110 net/ipv6/ip6_icmp.c:43 __udp6_lib_rcv+0x2a7c/0x4080 net/ipv6/udp.c:928 udpv6_rcv+0x5c/0x70 net/ipv6/udp.c:1017 ip6_protocol_deliver_rcu+0x14d6/0x22c0 net/ipv6/ip6_input.c:433 ip6_input_finish net/ipv6/ip6_input.c:474 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:483 dst_input include/net/dst.h:441 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:307 __netif_receive_skb_one_core net/core/dev.c:5188 [inline] __netif_receive_skb net/core/dev.c:5302 [inline] process_backlog+0xa41/0x1410 net/core/dev.c:6134 napi_poll net/core/dev.c:6572 [inline] net_rx_action+0x786/0x1aa0 net/core/dev.c:6640 __do_softirq+0x311/0x83d kernel/softirq.c:293 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 =====================================================