=====================================================
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+0x205/0x2630 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+0x253/0xa20 net/core/dev.c:3597
 __dev_queue_xmit+0x3c7f/0x5ac0 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+0x89c5/0x9ee0 net/packet/af_packet.c:3104
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
 ___sys_sendmsg+0x2a1/0x3f0 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+0x36b/0x540 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+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 include/linux/skbuff.h:1278 [inline]
 alloc_skb_with_frags+0xbd/0xbb0 net/core/skbuff.c:6318
 sock_alloc_send_pskb+0xaad/0xc30 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+0x716c/0x9ee0 net/packet/af_packet.c:3104
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501
 ___sys_sendmsg+0x2a1/0x3f0 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+0x36b/0x540 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: 21919 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
=====================================================