===================================================== BUG: KMSAN: uninit-value in ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2717 CPU: 1 PID: 30318 Comm: syz-executor.3 Not tainted 5.5.0-rc1-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+0xf8/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2717 __mkroute_output net/ipv4/route.c:2389 [inline] ip_route_output_key_hash_rcu+0x1d35/0x3910 net/ipv4/route.c:2671 ip_route_output_key_hash net/ipv4/route.c:2497 [inline] __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x1e2/0x3d0 net/ipv4/route.c:2759 ip_route_output_key include/net/route.h:136 [inline] ip_tunnel_xmit+0x12ce/0x3480 net/ipv4/ip_tunnel.c:753 __gre_xmit net/ipv4/ip_gre.c:448 [inline] ipgre_xmit+0xff3/0x1120 net/ipv4/ip_gre.c:632 __netdev_start_xmit include/linux/netdevice.h:4447 [inline] netdev_start_xmit include/linux/netdevice.h:4461 [inline] xmit_one net/core/dev.c:3420 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3436 __dev_queue_xmit+0x3837/0x4280 net/core/dev.c:4013 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046 packet_snd net/packet/af_packet.c:2965 [inline] packet_sendmsg+0x836f/0x92a0 net/packet/af_packet.c:2990 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45a919 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f795ab90c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f795ab916d4 R13: 00000000004c99b6 R14: 00000000004e1888 R15: 00000000ffffffff Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xc5/0x140 mm/kmsan/kmsan.c:310 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165 ip_tunnel_init_flow include/net/ip_tunnels.h:248 [inline] ip_tunnel_xmit+0xb0f/0x3480 net/ipv4/ip_tunnel.c:735 __gre_xmit net/ipv4/ip_gre.c:448 [inline] ipgre_xmit+0xff3/0x1120 net/ipv4/ip_gre.c:632 __netdev_start_xmit include/linux/netdevice.h:4447 [inline] netdev_start_xmit include/linux/netdevice.h:4461 [inline] xmit_one net/core/dev.c:3420 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3436 __dev_queue_xmit+0x3837/0x4280 net/core/dev.c:4013 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046 packet_snd net/packet/af_packet.c:2965 [inline] packet_sendmsg+0x836f/0x92a0 net/packet/af_packet.c:2990 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xc5/0x140 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x25c/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x44/0x50 mm/kmsan/kmsan_instr.c:116 pskb_expand_head+0x383/0x1b00 net/core/skbuff.c:1637 __skb_cow include/linux/skbuff.h:3120 [inline] skb_cow_head include/linux/skbuff.h:3154 [inline] ipgre_xmit+0x6d9/0x1120 net/ipv4/ip_gre.c:611 __netdev_start_xmit include/linux/netdevice.h:4447 [inline] netdev_start_xmit include/linux/netdevice.h:4461 [inline] xmit_one net/core/dev.c:3420 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3436 __dev_queue_xmit+0x3837/0x4280 net/core/dev.c:4013 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046 packet_snd net/packet/af_packet.c:2965 [inline] packet_sendmsg+0x836f/0x92a0 net/packet/af_packet.c:2990 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8b/0xe0 mm/kmsan/kmsan_hooks.c:82 slab_alloc_node mm/slub.c:2774 [inline] __kmalloc_node_track_caller+0xe47/0x11f0 mm/slub.c:4382 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x309/0xa50 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] alloc_skb_with_frags+0x18c/0xa80 net/core/skbuff.c:5664 sock_alloc_send_pskb+0xae9/0xc70 net/core/sock.c:2242 packet_alloc_skb net/packet/af_packet.c:2813 [inline] packet_snd net/packet/af_packet.c:2908 [inline] packet_sendmsg+0x6562/0x92a0 net/packet/af_packet.c:2990 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330 ___sys_sendmsg net/socket.c:2384 [inline] __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================