=====================================================
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
 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4344
 dev_queue_xmit include/linux/netdevice.h:3112 [inline]
 garp_queue_xmit net/802/garp.c:273 [inline]
 garp_join_timer+0x18e/0x2e0 net/802/garp.c:424
 call_timer_fn+0x45/0x570 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x850/0xf60 kernel/time/timer.c:2022
 run_timer_softirq+0x26/0x40 kernel/time/timer.c:2035
 __do_softirq+0x1b7/0x7c3 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0x69/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x7a/0x90 arch/x86/kernel/apic/apic.c:1076
 asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:645
 __sanitizer_cov_trace_pc+0x5/0x70 kernel/kcov.c:200
 console_emit_next_record kernel/printk/printk.c:2868 [inline]
 console_flush_all+0x42f/0x13e0 kernel/printk/printk.c:2967
 console_unlock+0xaa/0x4f0 kernel/printk/printk.c:3036
 vprintk_emit+0x5be/0xbd0 kernel/printk/printk.c:2303
 vprintk_default+0x3e/0x50 kernel/printk/printk.c:2318
 vprintk+0xea/0xf0 kernel/printk/printk_safe.c:45
 _printk+0x157/0x190 kernel/printk/printk.c:2328
 __netdev_printk+0x50f/0x960 net/core/dev.c:11387
 netdev_info+0x18a/0x1a0 net/core/dev.c:11434
 __dev_set_promiscuity+0x407/0x9b0 net/core/dev.c:8394
 __dev_change_flags+0x6a7/0x930 net/core/dev.c:8612
 rtnl_configure_link net/core/rtnetlink.c:3332 [inline]
 rtnl_newlink_create net/core/rtnetlink.c:3529 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3741 [inline]
 rtnl_newlink+0x30e4/0x4110 net/core/rtnetlink.c:3754
 rtnetlink_rcv_msg+0x16a6/0x1840 net/core/rtnetlink.c:6558
 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6576
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
 __sys_sendmsg net/socket.c:2667 [inline]
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

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+0x5c9/0x970 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0x118/0x3c0 mm/slab_common.c:1027
 kmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:582
 __alloc_skb+0x318/0x740 net/core/skbuff.c:651
 alloc_skb include/linux/skbuff.h:1286 [inline]
 garp_pdu_init net/802/garp.c:226 [inline]
 garp_pdu_append_attr+0x299/0x1170 net/802/garp.c:297
 garp_attr_event+0x146/0x280 net/802/garp.c:339
 garp_gid_event net/802/garp.c:403 [inline]
 garp_join_timer+0xc5/0x2e0 net/802/garp.c:420
 call_timer_fn+0x45/0x570 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x850/0xf60 kernel/time/timer.c:2022
 run_timer_softirq+0x26/0x40 kernel/time/timer.c:2035
 __do_softirq+0x1b7/0x7c3 kernel/softirq.c:553

CPU: 1 PID: 20076 Comm: syz-executor.1 Not tainted 6.6.0-syzkaller-16201-gb57b17e88bf5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
=====================================================