=====================================================
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:4889 [inline]
 netdev_start_xmit include/linux/netdevice.h:4903 [inline]
 xmit_one net/core/dev.c:3544 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3560
 __dev_queue_xmit+0x34bb/0x52b0 net/core/dev.c:4340
 dev_queue_xmit include/linux/netdevice.h:3082 [inline]
 __bpf_tx_skb net/core/filter.c:2129 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2159 [inline]
 __bpf_redirect+0xdf7/0x1700 net/core/filter.c:2182
 ____bpf_clone_redirect net/core/filter.c:2453 [inline]
 bpf_clone_redirect+0x328/0x470 net/core/filter.c:2425
 ___bpf_prog_run+0x2180/0xdb80 kernel/bpf/core.c:1954
 __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2195
 bpf_dispatcher_nop_func include/linux/bpf.h:1181 [inline]
 __bpf_prog_run include/linux/filter.h:609 [inline]
 bpf_prog_run include/linux/filter.h:616 [inline]
 bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
 bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1046
 bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:3996
 __sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5353
 __do_sys_bpf kernel/bpf/syscall.c:5439 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5437 [inline]
 __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5437
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
 pskb_expand_head+0x226/0x1a00 net/core/skbuff.c:2093
 skb_ensure_writable+0x3d3/0x460 net/core/skbuff.c:5940
 __bpf_try_make_writable net/core/filter.c:1658 [inline]
 bpf_try_make_writable net/core/filter.c:1664 [inline]
 bpf_try_make_head_writable net/core/filter.c:1672 [inline]
 ____bpf_clone_redirect net/core/filter.c:2447 [inline]
 bpf_clone_redirect+0x17f/0x470 net/core/filter.c:2425
 ___bpf_prog_run+0x2180/0xdb80 kernel/bpf/core.c:1954
 __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2195
 bpf_dispatcher_nop_func include/linux/bpf.h:1181 [inline]
 __bpf_prog_run include/linux/filter.h:609 [inline]
 bpf_prog_run include/linux/filter.h:616 [inline]
 bpf_test_run+0x482/0xb00 net/bpf/test_run.c:423
 bpf_prog_test_run_skb+0x14e5/0x1f20 net/bpf/test_run.c:1046
 bpf_prog_test_run+0x6af/0xac0 kernel/bpf/syscall.c:3996
 __sys_bpf+0x649/0xd60 kernel/bpf/syscall.c:5353
 __do_sys_bpf kernel/bpf/syscall.c:5439 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5437 [inline]
 __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5437
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 0 PID: 7542 Comm: syz-executor.1 Not tainted 6.6.0-rc4-syzkaller-00012-gce36c8b14987 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
=====================================================