===================================================== BUG: KMSAN: uninit-value in ip_check_mc_rcu+0x2a5/0x670 net/ipv4/igmp.c:2717 CPU: 0 PID: 20754 Comm: syz-executor.5 Not tainted 5.4.0-rc5+ #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+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108 __msan_warning+0x73/0xe0 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:4420 [inline] netdev_start_xmit include/linux/netdevice.h:4434 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3296 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3873 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3906 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x82d7/0x92e0 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+0x63/0xe7 RIP: 0033:0x459f49 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:00007f9ff067ec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ff067f6d4 R13: 00000000004c83d4 R14: 00000000004de968 R15: 00000000ffffffff Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline] kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:319 __msan_chain_origin+0x6b/0xd0 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:4420 [inline] netdev_start_xmit include/linux/netdevice.h:4434 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3296 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3873 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3906 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x82d7/0x92e0 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+0x63/0xe7 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline] kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:319 kmsan_memcpy_memmove_metadata+0x25c/0x2e0 mm/kmsan/kmsan.c:254 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:274 __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:3105 [inline] skb_cow_head include/linux/skbuff.h:3139 [inline] ipgre_xmit+0x6d9/0x1120 net/ipv4/ip_gre.c:607 __netdev_start_xmit include/linux/netdevice.h:4420 [inline] netdev_start_xmit include/linux/netdevice.h:4434 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3296 __dev_queue_xmit+0x35b6/0x4200 net/core/dev.c:3873 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3906 packet_snd net/packet/af_packet.c:2959 [inline] packet_sendmsg+0x82d7/0x92e0 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+0x63/0xe7 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline] kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:134 kmsan_slab_alloc+0xaa/0x120 mm/kmsan/kmsan_hooks.c:88 slab_alloc_node mm/slub.c:2799 [inline] __kmalloc_node_track_caller+0xd7b/0x1390 mm/slub.c:4408 __kmalloc_reserve net/core/skbuff.c:141 [inline] __alloc_skb+0x306/0xa10 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1050 [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+0x6785/0x92e0 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+0x63/0xe7 =====================================================