=====================================================
BUG: KMSAN: uninit-value in decode_session4 net/xfrm/xfrm_policy.c:3381 [inline]
BUG: KMSAN: uninit-value in __xfrm_decode_session+0x16ba/0x2890 net/xfrm/xfrm_policy.c:3552
 decode_session4 net/xfrm/xfrm_policy.c:3381 [inline]
 __xfrm_decode_session+0x16ba/0x2890 net/xfrm/xfrm_policy.c:3552
 xfrm_decode_session include/net/xfrm.h:1210 [inline]
 xfrmi_xmit+0x1d7/0x2310 net/xfrm/xfrm_interface_core.c:554
 __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+0x247/0xa10 net/core/dev.c:3597
 __dev_queue_xmit+0x38b1/0x5460 net/core/dev.c:4247
 dev_queue_xmit+0x2f/0x40 include/linux/netdevice.h:3054
 packet_snd net/packet/af_packet.c:3073 [inline]
 packet_sendmsg+0x87d0/0x9c60 net/packet/af_packet.c:3104
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x999/0xd50 net/socket.c:2501
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2555
 __sys_sendmsg net/socket.c:2584 [inline]
 __do_sys_sendmsg net/socket.c:2593 [inline]
 __se_sys_sendmsg net/socket.c:2591 [inline]
 __x64_sys_sendmsg+0x304/0x490 net/socket.c:2591
 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+0x535/0xa30 mm/slub.c:3497
 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:520
 __alloc_skb+0x318/0x740 net/core/skbuff.c:606
 alloc_skb include/linux/skbuff.h:1278 [inline]
 alloc_skb_with_frags+0xbd/0xbb0 net/core/skbuff.c:6318
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2734
 packet_alloc_skb net/packet/af_packet.c:2921 [inline]
 packet_snd net/packet/af_packet.c:3016 [inline]
 packet_sendmsg+0x702c/0x9c60 net/packet/af_packet.c:3104
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x999/0xd50 net/socket.c:2501
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2555
 __sys_sendmsg net/socket.c:2584 [inline]
 __do_sys_sendmsg net/socket.c:2593 [inline]
 __se_sys_sendmsg net/socket.c:2591 [inline]
 __x64_sys_sendmsg+0x304/0x490 net/socket.c:2591
 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

CPU: 1 PID: 12549 Comm: syz-executor.4 Not tainted 6.3.0-syzkaller-g81af97bdef5e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
=====================================================