===================================================== BUG: KMSAN: uninit-value in kmsan_check_skb+0x3c/0x240 mm/kmsan/kmsan_hooks.c:275 CPU: 0 PID: 2793 Comm: syz-executor.2 Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x24c/0x2e0 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121 kmsan_internal_check_memory+0x1f5/0x500 mm/kmsan/kmsan.c:399 kmsan_check_skb+0x3c/0x240 mm/kmsan/kmsan_hooks.c:275 pfifo_fast_dequeue+0x1031/0x1190 net/sched/sch_generic.c:659 dequeue_skb+0x4ad/0x3680 net/sched/sch_generic.c:264 qdisc_restart net/sched/sch_generic.c:367 [inline] __qdisc_run+0x101/0x490 net/sched/sch_generic.c:385 qdisc_run include/net/pkt_sched.h:136 [inline] __dev_xmit_skb net/core/dev.c:3807 [inline] __dev_queue_xmit+0x26ad/0x4600 net/core/dev.c:4162 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 neigh_resolve_output+0xc65/0xcf0 net/core/neighbour.c:1491 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x1d16/0x2930 net/ipv4/ip_output.c:230 __ip_finish_output+0x9fd/0x1050 net/ipv4/ip_output.c:252 ip_finish_output+0x329/0x480 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_mc_output+0xae0/0x1260 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:448 [inline] ip_local_out+0x17b/0x1e0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x931/0xf20 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x382f/0x3a20 net/ipv4/ip_tunnel.c:804 __gre_xmit net/ipv4/ip_gre.c:466 [inline] erspan_xmit+0x2641/0x3ea0 net/ipv4/ip_gre.c:702 __netdev_start_xmit include/linux/netdevice.h:4825 [inline] netdev_start_xmit include/linux/netdevice.h:4839 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3605 dev_hard_start_xmit+0x196/0x420 net/core/dev.c:3621 sch_direct_xmit+0x57c/0x1a60 net/sched/sch_generic.c:314 qdisc_restart net/sched/sch_generic.c:377 [inline] __qdisc_run+0x35b/0x490 net/sched/sch_generic.c:385 qdisc_run include/net/pkt_sched.h:136 [inline] __dev_xmit_skb net/core/dev.c:3807 [inline] __dev_queue_xmit+0x26ad/0x4600 net/core/dev.c:4162 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 neigh_resolve_output+0xc65/0xcf0 net/core/neighbour.c:1491 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x1d16/0x2930 net/ipv4/ip_output.c:230 __ip_finish_output+0x9fd/0x1050 net/ipv4/ip_output.c:252 ip_finish_output+0x329/0x480 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_mc_output+0xae0/0x1260 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:448 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x194/0x350 net/ipv4/ip_output.c:1568 udp_send_skb+0x152d/0x1bc0 net/ipv4/udp.c:953 udp_sendmsg+0x3e93/0x4920 net/ipv4/udp.c:1240 udpv6_sendmsg+0x1bd3/0x54f0 net/ipv6/udp.c:1345 inet6_sendmsg+0x15b/0x1d0 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0xa57/0x1010 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2516 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2516 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe2a90a2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 04000000000000d7 RSI: 00000000200002c0 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 0000000000a9fb1f R14: 00007fe2a90a2300 R15: 0000000000022000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:288 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:225 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:245 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110 pskb_expand_head+0x3d6/0x1e20 net/core/skbuff.c:1685 __skb_cow include/linux/skbuff.h:3232 [inline] skb_cow_head include/linux/skbuff.h:3266 [inline] ip_tunnel_xmit+0x344b/0x3a20 net/ipv4/ip_tunnel.c:797 __gre_xmit net/ipv4/ip_gre.c:466 [inline] erspan_xmit+0x2641/0x3ea0 net/ipv4/ip_gre.c:702 __netdev_start_xmit include/linux/netdevice.h:4825 [inline] netdev_start_xmit include/linux/netdevice.h:4839 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3605 dev_hard_start_xmit+0x196/0x420 net/core/dev.c:3621 sch_direct_xmit+0x57c/0x1a60 net/sched/sch_generic.c:314 qdisc_restart net/sched/sch_generic.c:377 [inline] __qdisc_run+0x35b/0x490 net/sched/sch_generic.c:385 qdisc_run include/net/pkt_sched.h:136 [inline] __dev_xmit_skb net/core/dev.c:3807 [inline] __dev_queue_xmit+0x26ad/0x4600 net/core/dev.c:4162 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 neigh_resolve_output+0xc65/0xcf0 net/core/neighbour.c:1491 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x1d16/0x2930 net/ipv4/ip_output.c:230 __ip_finish_output+0x9fd/0x1050 net/ipv4/ip_output.c:252 ip_finish_output+0x329/0x480 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_mc_output+0xae0/0x1260 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:448 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x194/0x350 net/ipv4/ip_output.c:1568 udp_send_skb+0x152d/0x1bc0 net/ipv4/udp.c:953 udp_sendmsg+0x3e93/0x4920 net/ipv4/udp.c:1240 udpv6_sendmsg+0x1bd3/0x54f0 net/ipv6/udp.c:1345 inet6_sendmsg+0x15b/0x1d0 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0xa57/0x1010 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2516 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2516 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:120 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:103 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node_track_caller+0xa4f/0x1470 mm/slub.c:4609 kmalloc_reserve net/core/skbuff.c:353 [inline] __alloc_skb+0x4dd/0xe90 net/core/skbuff.c:424 alloc_skb include/linux/skbuff.h:1103 [inline] alloc_skb_with_frags+0x1f3/0xc10 net/core/skbuff.c:5948 sock_alloc_send_pskb+0xdc1/0xf90 net/core/sock.c:2362 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2379 __ip_append_data+0x417c/0x6320 net/ipv4/ip_output.c:1098 ip_make_skb+0x409/0x920 net/ipv4/ip_output.c:1634 udp_sendmsg+0x3d94/0x4920 net/ipv4/udp.c:1235 udpv6_sendmsg+0x1bd3/0x54f0 net/ipv6/udp.c:1345 inet6_sendmsg+0x15b/0x1d0 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0xa57/0x1010 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2516 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2516 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 38-41 of 92 are uninitialized Memory access of size 92 starts at ffff88815d3a70c0 =====================================================