=====================================================
BUG: KMSAN: uninit-value in vlan_dev_hard_start_xmit+0x1c9/0xa00 net/8021q/vlan_dev.c:111
CPU: 0 PID: 1433 Comm: kworker/u4:16 Not tainted 5.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_mcast_mla_update
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:201
 vlan_dev_hard_start_xmit+0x1c9/0xa00 net/8021q/vlan_dev.c:111
 __netdev_start_xmit include/linux/netdevice.h:4634 [inline]
 netdev_start_xmit include/linux/netdevice.h:4648 [inline]
 xmit_one+0x3cf/0x750 net/core/dev.c:3561
 dev_hard_start_xmit net/core/dev.c:3577 [inline]
 __dev_queue_xmit+0x3aad/0x4470 net/core/dev.c:4136
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4169
 garp_queue_xmit net/802/garp.c:259 [inline]
 garp_join_timer+0x1fc/0x380 net/802/garp.c:410
 call_timer_fn+0x226/0x550 kernel/time/timer.c:1413
 expire_timers+0x4fc/0x780 kernel/time/timer.c:1458
 __run_timers+0x624/0x9e0 kernel/time/timer.c:1755
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1768
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:299
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:23 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline]
 do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77
 do_softirq kernel/softirq.c:344 [inline]
 __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:196
 __raw_read_unlock_bh include/linux/rwlock_api_smp.h:251 [inline]
 _raw_read_unlock_bh+0x5d/0x80 kernel/locking/spinlock.c:279
 batadv_mcast_mla_softif_get_ipv6 net/batman-adv/multicast.c:487 [inline]
 batadv_mcast_mla_softif_get net/batman-adv/multicast.c:536 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:911 [inline]
 batadv_mcast_mla_update+0x29d8/0x5fa0 net/batman-adv/multicast.c:948
 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269
 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415
 kthread+0x551/0x590 kernel/kthread.c:293
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2907 [inline]
 __kmalloc_node_track_caller+0x9aa/0x12f0 mm/slub.c:4511
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 garp_pdu_init net/802/garp.c:212 [inline]
 garp_pdu_append_attr+0x30d/0x1400 net/802/garp.c:283
 garp_attr_event+0x25d/0x360 net/802/garp.c:325
 garp_gid_event net/802/garp.c:389 [inline]
 garp_join_timer+0x10e/0x380 net/802/garp.c:406
 call_timer_fn+0x226/0x550 kernel/time/timer.c:1413
 expire_timers+0x4fc/0x780 kernel/time/timer.c:1458
 __run_timers+0x624/0x9e0 kernel/time/timer.c:1755
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1768
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:299
=====================================================