===================================================== BUG: KMSAN: uninit-value in ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2717 CPU: 0 PID: 4136 Comm: syz-executor.3 Not tainted 5.4.0-rc8-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+0x128/0x220 mm/kmsan/kmsan_report.c:108 __msan_warning+0x64/0xc0 mm/kmsan/kmsan_instr.c:245 ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2717 __mkroute_output net/ipv4/route.c:2350 [inline] ip_route_output_key_hash_rcu+0x1d35/0x3910 net/ipv4/route.c:2632 ip_route_output_key_hash net/ipv4/route.c:2458 [inline] __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x1e2/0x3d0 net/ipv4/route.c:2720 ip_route_output_key include/net/route.h:136 [inline] ip_tunnel_xmit+0x127e/0x3320 net/ipv4/ip_tunnel.c:753 __gre_xmit net/ipv4/ip_gre.c:444 [inline] ipgre_xmit+0xff3/0x1120 net/ipv4/ip_gre.c:628 __netdev_start_xmit include/linux/netdevice.h:4413 [inline] netdev_start_xmit include/linux/netdevice.h:4427 [inline] xmit_one net/core/dev.c:3199 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3215 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3792 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3825 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x8234/0x9100 net/packet/af_packet.c:2984 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] ___sys_sendmsg+0x14ff/0x1590 net/socket.c:2311 __sys_sendmsg net/socket.c:2356 [inline] __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg+0x305/0x460 net/socket.c:2363 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45a639 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:00007f97999b4c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f97999b56d4 R13: 00000000004c8d02 R14: 00000000004df538 R15: 00000000ffffffff Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline] kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:317 __msan_chain_origin+0x5c/0xc0 mm/kmsan/kmsan_instr.c:179 ip_tunnel_init_flow include/net/ip_tunnels.h:248 [inline] ip_tunnel_xmit+0x9ee/0x3320 net/ipv4/ip_tunnel.c:735 __gre_xmit net/ipv4/ip_gre.c:444 [inline] ipgre_xmit+0xff3/0x1120 net/ipv4/ip_gre.c:628 __netdev_start_xmit include/linux/netdevice.h:4413 [inline] netdev_start_xmit include/linux/netdevice.h:4427 [inline] xmit_one net/core/dev.c:3199 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3215 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3792 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3825 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x8234/0x9100 net/packet/af_packet.c:2984 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] ___sys_sendmsg+0x14ff/0x1590 net/socket.c:2311 __sys_sendmsg net/socket.c:2356 [inline] __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg+0x305/0x460 net/socket.c:2363 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline] kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:317 kmsan_memcpy_memmove_metadata+0x25c/0x2e0 mm/kmsan/kmsan.c:252 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:272 __msan_memcpy+0x56/0x70 mm/kmsan/kmsan_instr.c:129 pskb_expand_head+0x38a/0x19f0 net/core/skbuff.c:1637 __skb_cow include/linux/skbuff.h:3118 [inline] skb_cow_head include/linux/skbuff.h:3152 [inline] ipgre_xmit+0x6d9/0x1120 net/ipv4/ip_gre.c:607 __netdev_start_xmit include/linux/netdevice.h:4413 [inline] netdev_start_xmit include/linux/netdevice.h:4427 [inline] xmit_one net/core/dev.c:3199 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3215 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3792 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3825 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x8234/0x9100 net/packet/af_packet.c:2984 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] ___sys_sendmsg+0x14ff/0x1590 net/socket.c:2311 __sys_sendmsg net/socket.c:2356 [inline] __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg+0x305/0x460 net/socket.c:2363 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline] kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:132 kmsan_slab_alloc+0x97/0x100 mm/kmsan/kmsan_hooks.c:86 slab_alloc_node mm/slub.c:2773 [inline] __kmalloc_node_track_caller+0xe27/0x11a0 mm/slub.c:4381 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x306/0xa10 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] alloc_skb_with_frags+0x18c/0xa80 net/core/skbuff.c:5662 sock_alloc_send_pskb+0xafd/0x10a0 net/core/sock.c:2244 packet_alloc_skb net/packet/af_packet.c:2807 [inline] packet_snd net/packet/af_packet.c:2902 [inline] packet_sendmsg+0x63a6/0x9100 net/packet/af_packet.c:2984 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] ___sys_sendmsg+0x14ff/0x1590 net/socket.c:2311 __sys_sendmsg net/socket.c:2356 [inline] __do_sys_sendmsg net/socket.c:2365 [inline] __se_sys_sendmsg+0x305/0x460 net/socket.c:2363 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2363 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================