=====================================================
BUG: KMSAN: uninit-value in decode_session4 net/xfrm/xfrm_policy.c:3391 [inline]
BUG: KMSAN: uninit-value in __xfrm_decode_session+0x16ba/0x2890 net/xfrm/xfrm_policy.c:3562
 decode_session4 net/xfrm/xfrm_policy.c:3391 [inline]
 __xfrm_decode_session+0x16ba/0x2890 net/xfrm/xfrm_policy.c:3562
 xfrm_decode_session include/net/xfrm.h:1216 [inline]
 xfrmi_xmit+0x1ea/0x2270 net/xfrm/xfrm_interface_core.c:556
 __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+0x34d0/0x52a0 net/core/dev.c:4340
 dev_queue_xmit include/linux/netdevice.h:3082 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594
 __sys_sendmsg net/socket.c:2623 [inline]
 __do_sys_sendmsg net/socket.c:2632 [inline]
 __se_sys_sendmsg net/socket.c:2630 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630
 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+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+0x148/0x470 net/core/skbuff.c:559
 __alloc_skb+0x318/0x740 net/core/skbuff.c:644
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6299
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2794
 packet_alloc_skb net/packet/af_packet.c:2936 [inline]
 packet_snd net/packet/af_packet.c:3030 [inline]
 packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594
 __sys_sendmsg net/socket.c:2623 [inline]
 __do_sys_sendmsg net/socket.c:2632 [inline]
 __se_sys_sendmsg net/socket.c:2630 [inline]
 __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630
 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: 6571 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-04808-g6c1b980a7e79 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
=====================================================