netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'.
=====================================================
BUG: KMSAN: uninit-value in ip_tunnel_xmit+0x857/0x3e80 net/ipv4/ip_tunnel.c:679
 ip_tunnel_xmit+0x857/0x3e80 net/ipv4/ip_tunnel.c:679
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 ipgre_xmit+0xd1c/0xe20 net/ipv4/ip_gre.c:662
 __netdev_start_xmit include/linux/netdevice.h:4918 [inline]
 netdev_start_xmit include/linux/netdevice.h:4932 [inline]
 xmit_one net/core/dev.c:3543 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3559
 sch_direct_xmit+0x3c5/0xd40 net/sched/sch_generic.c:342
 qdisc_restart net/sched/sch_generic.c:407 [inline]
 __qdisc_run+0x14ab/0x35a0 net/sched/sch_generic.c:415
 __dev_xmit_skb net/core/dev.c:3833 [inline]
 __dev_queue_xmit+0x1b51/0x5130 net/core/dev.c:4310
 dev_queue_xmit include/linux/netdevice.h:3112 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x781/0xa30 net/socket.c:2194
 __do_sys_sendto net/socket.c:2206 [inline]
 __se_sys_sendto net/socket.c:2202 [inline]
 __ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2202
 do_syscall_32_irqs_on arch/x86/entry/common.c:164 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:230
 do_fast_syscall_32+0x37/0x70 arch/x86/entry/common.c:255
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:293
 entry_SYSENTER_compat_after_hwframe+0x70/0x7a

Uninit was created at:
 slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
 pskb_expand_head+0x226/0x1a00 net/core/skbuff.c:2098
 __skb_cow include/linux/skbuff.h:3586 [inline]
 skb_cow_head include/linux/skbuff.h:3620 [inline]
 ipgre_xmit+0x74a/0xe20 net/ipv4/ip_gre.c:638
 __netdev_start_xmit include/linux/netdevice.h:4918 [inline]
 netdev_start_xmit include/linux/netdevice.h:4932 [inline]
 xmit_one net/core/dev.c:3543 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3559
 sch_direct_xmit+0x3c5/0xd40 net/sched/sch_generic.c:342
 qdisc_restart net/sched/sch_generic.c:407 [inline]
 __qdisc_run+0x14ab/0x35a0 net/sched/sch_generic.c:415
 __dev_xmit_skb net/core/dev.c:3833 [inline]
 __dev_queue_xmit+0x1b51/0x5130 net/core/dev.c:4310
 dev_queue_xmit include/linux/netdevice.h:3112 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x781/0xa30 net/socket.c:2194
 __do_sys_sendto net/socket.c:2206 [inline]
 __se_sys_sendto net/socket.c:2202 [inline]
 __ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2202
 do_syscall_32_irqs_on arch/x86/entry/common.c:164 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:230
 do_fast_syscall_32+0x37/0x70 arch/x86/entry/common.c:255
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:293
 entry_SYSENTER_compat_after_hwframe+0x70/0x7a

CPU: 1 PID: 5242 Comm: syz-executor.0 Not tainted 6.6.0-syzkaller-15601-g4bbdb725a36b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
=====================================================