=====================================================
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
 smap_restore arch/x86/include/asm/smap.h:56 [inline]
 get_shadow_origin_ptr mm/kmsan/instrumentation.c:37 [inline]
 __msan_metadata_ptr_for_load_8+0x2c/0x40 mm/kmsan/instrumentation.c:92
 on_stack+0x3a/0x1b0
 update_stack_state+0xc1/0x270 arch/x86/kernel/unwind_frame.c:228
 unwind_next_frame+0x1a2/0x480 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x1df/0x2c0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0xe0 kernel/stacktrace.c:122
 kmsan_save_stack_with_flags mm/kmsan/core.c:74 [inline]
 kmsan_internal_poison_memory+0x49/0xa0 mm/kmsan/core.c:58
 kmsan_slab_free+0xd1/0x130 mm/kmsan/hooks.c:89
 slab_free_hook mm/slub.c:1770 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 kmem_cache_free_bulk+0x1370/0x1e50 mm/slub.c:3927
 kfree_bulk include/linux/slab.h:517 [inline]
 kvfree_rcu_bulk+0x204/0x590 kernel/rcu/tree.c:2990
 kvfree_rcu_drain_ready kernel/rcu/tree.c:3164 [inline]
 kfree_rcu_monitor+0xf89/0x22f0 kernel/rcu/tree.c:3182
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3ed/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

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: 5088 Comm: kworker/1:4 Tainted: G        W          6.6.0-syzkaller-16201-gb57b17e88bf5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events kfree_rcu_monitor
=====================================================