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BUG: KMSAN: uninit-value in ip_tunnel_xmit+0x8f1/0x4230 net/ipv4/ip_tunnel.c:661
 ip_tunnel_xmit+0x8f1/0x4230 net/ipv4/ip_tunnel.c:661
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 ipgre_xmit+0xd29/0xe30 net/ipv4/ip_gre.c:661
 __netdev_start_xmit include/linux/netdevice.h:4884 [inline]
 netdev_start_xmit include/linux/netdevice.h:4898 [inline]
 xmit_one net/core/dev.c:3581 [inline]
 dev_hard_start_xmit+0x253/0xa20 net/core/dev.c:3597
 __dev_queue_xmit+0x3c7f/0x5ac0 net/core/dev.c:4247
 dev_queue_xmit include/linux/netdevice.h:3054 [inline]
 garp_queue_xmit net/802/garp.c:272 [inline]
 garp_join_timer+0x18e/0x2e0 net/802/garp.c:423
 call_timer_fn+0x45/0x4e0 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x861/0xf90 kernel/time/timer.c:2022
 run_timer_softirq+0x68/0xe0 kernel/time/timer.c:2035
 __do_softirq+0x1c9/0x7c5 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0xe5/0x220 kernel/softirq.c:650
 irq_exit_rcu+0x12/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1107
 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_store_8+0x2f/0x40 mm/kmsan/instrumentation.c:92
 update_stack_state+0x183/0x1e0
 unwind_next_frame+0x11d/0x360 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x1bd/0x290 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xb6/0x100 kernel/stacktrace.c:122
 kmsan_save_stack_with_flags mm/kmsan/core.c:76 [inline]
 kmsan_internal_poison_memory+0x49/0xa0 mm/kmsan/core.c:60
 kmsan_slab_alloc+0xdd/0x150 mm/kmsan/hooks.c:68
 slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
 slab_alloc_node mm/slub.c:3452 [inline]
 kmem_cache_alloc_node+0x543/0xab0 mm/slub.c:3497
 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:520
 __alloc_skb+0x3a7/0x850 net/core/skbuff.c:606
 alloc_skb_fclone include/linux/skbuff.h:1328 [inline]
 tcp_stream_alloc_skb+0x54/0x5c0 net/ipv4/tcp.c:863
 tcp_sendmsg_locked+0x1842/0x6360 net/ipv4/tcp.c:1326
 tcp_sendmsg+0x49/0x80 net/ipv4/tcp.c:1484
 inet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:825
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 sock_write_iter+0x4b0/0x660 net/socket.c:1138
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x834/0x1580 fs/read_write.c:584
 ksys_write+0x21f/0x4f0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x93/0xd0 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
 slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x518/0x920 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc_node_track_caller+0x118/0x3c0 mm/slab_common.c:987
 kmalloc_reserve+0x248/0x470 net/core/skbuff.c:537
 __alloc_skb+0x3a7/0x850 net/core/skbuff.c:606
 alloc_skb include/linux/skbuff.h:1278 [inline]
 garp_pdu_init net/802/garp.c:225 [inline]
 garp_pdu_append_attr+0x299/0x1170 net/802/garp.c:296
 garp_attr_event+0x146/0x280 net/802/garp.c:338
 garp_gid_event net/802/garp.c:402 [inline]
 garp_join_timer+0xc5/0x2e0 net/802/garp.c:419
 call_timer_fn+0x45/0x4e0 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x861/0xf90 kernel/time/timer.c:2022
 run_timer_softirq+0x68/0xe0 kernel/time/timer.c:2035
 __do_softirq+0x1c9/0x7c5 kernel/softirq.c:571

CPU: 0 PID: 4951 Comm: sshd Not tainted 6.3.0-syzkaller-g81af97bdef5e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
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