================================================================== BUG: KMSAN: uninit-value in ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2702 CPU: 1 PID: 15020 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #61 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+0x2f6/0x430 lib/dump_stack.c:113 kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:917 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:500 ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2702 __mkroute_output net/ipv4/route.c:2223 [inline] ip_route_output_key_hash_rcu+0x1f18/0x3b00 net/ipv4/route.c:2502 ip_route_output_key_hash net/ipv4/route.c:2331 [inline] __ip_route_output_key include/net/route.h:124 [inline] ip_route_output_flow+0x1d2/0x3a0 net/ipv4/route.c:2586 ip_route_output_key include/net/route.h:134 [inline] ip_tunnel_xmit+0x12c4/0x3870 net/ipv4/ip_tunnel.c:717 __gre_xmit net/ipv4/ip_gre.c:454 [inline] ipgre_xmit+0xf24/0x1020 net/ipv4/ip_gre.c:708 __netdev_start_xmit include/linux/netdevice.h:4287 [inline] netdev_start_xmit include/linux/netdevice.h:4296 [inline] xmit_one net/core/dev.c:3216 [inline] dev_hard_start_xmit+0x68b/0xd50 net/core/dev.c:3232 __dev_queue_xmit+0x2d81/0x3c60 net/core/dev.c:3802 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3835 packet_snd net/packet/af_packet.c:2925 [inline] packet_sendmsg+0x8247/0x8db0 net/packet/af_packet.c:2950 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x457579 Code: 1d b4 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2b99ca3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000000 RSI: 00000000200004c0 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2b99ca46d4 R13: 00000000004c3837 R14: 00000000004d5640 R15: 00000000ffffffff Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_save_stack mm/kmsan/kmsan.c:270 [inline] kmsan_internal_chain_origin+0x128/0x210 mm/kmsan/kmsan.c:572 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:337 ip_tunnel_init_flow include/net/ip_tunnels.h:267 [inline] ip_tunnel_xmit+0xa41/0x3870 net/ipv4/ip_tunnel.c:706 __gre_xmit net/ipv4/ip_gre.c:454 [inline] ipgre_xmit+0xf24/0x1020 net/ipv4/ip_gre.c:708 __netdev_start_xmit include/linux/netdevice.h:4287 [inline] netdev_start_xmit include/linux/netdevice.h:4296 [inline] xmit_one net/core/dev.c:3216 [inline] dev_hard_start_xmit+0x68b/0xd50 net/core/dev.c:3232 __dev_queue_xmit+0x2d81/0x3c60 net/core/dev.c:3802 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3835 packet_snd net/packet/af_packet.c:2925 [inline] packet_sendmsg+0x8247/0x8db0 net/packet/af_packet.c:2950 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_save_stack mm/kmsan/kmsan.c:270 [inline] kmsan_internal_chain_origin+0x128/0x210 mm/kmsan/kmsan.c:572 kmsan_memcpy_origins+0x13d/0x1b0 mm/kmsan/kmsan.c:396 __msan_memcpy+0xc3/0x130 mm/kmsan/kmsan_instr.c:286 pskb_expand_head+0x49f/0x1e10 net/core/skbuff.c:1470 __skb_cow include/linux/skbuff.h:2911 [inline] skb_cow_head include/linux/skbuff.h:2945 [inline] ipgre_xmit+0x52d/0x1020 net/ipv4/ip_gre.c:687 __netdev_start_xmit include/linux/netdevice.h:4287 [inline] netdev_start_xmit include/linux/netdevice.h:4296 [inline] xmit_one net/core/dev.c:3216 [inline] dev_hard_start_xmit+0x68b/0xd50 net/core/dev.c:3232 __dev_queue_xmit+0x2d81/0x3c60 net/core/dev.c:3802 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3835 packet_snd net/packet/af_packet.c:2925 [inline] packet_sendmsg+0x8247/0x8db0 net/packet/af_packet.c:2950 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:180 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:93 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:102 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2727 [inline] __kmalloc_node_track_caller+0xba6/0x13f0 mm/slub.c:4360 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x40d/0xe50 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:996 [inline] alloc_skb_with_frags+0x1d0/0xac0 net/core/skbuff.c:5273 sock_alloc_send_pskb+0xe28/0x1420 net/core/sock.c:2082 packet_alloc_skb net/packet/af_packet.c:2779 [inline] packet_snd net/packet/af_packet.c:2870 [inline] packet_sendmsg+0x66b0/0x8db0 net/packet/af_packet.c:2950 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ==================================================================