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BUG: KMSAN: uninit-value in sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3701
 sctp_sf_ootb+0x7f5/0xce0 net/sctp/sm_statefuns.c:3701
 sctp_do_sm+0x17d/0x92d0 net/sctp/sm_sideeffect.c:1166
 sctp_endpoint_bh_rcv+0xc38/0xf90 net/sctp/endpointola.c:407
 sctp_inq_push+0x23e/0x2b0 net/sctp/inqueue.c:80
 sctp_rcv+0x3815/0x3a60 net/sctp/input.c:243
 sctp4_rcv+0x42/0x50 net/sctp/protocol.c:1160
 ip_protocol_deliver_rcu+0x264/0x1300 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2b8/0x440 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:303 [inline]
 ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:468 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
 NF_HOOK include/linux/netfilter.h:303 [inline]
 ip_rcv+0x476/0x770 net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5491 [inline]
 __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5605
 netif_receive_skb_internal net/core/dev.c:5691 [inline]
 netif_receive_skb+0x58/0x660 net/core/dev.c:5750
 tun_rx_batched+0x83b/0x920
 tun_get_user+0x54ca/0x6920 drivers/net/tun.c:1997
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2043
 call_write_iter include/linux/fs.h:1868 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8f9/0x1490 fs/read_write.c:584
 ksys_write+0x20f/0x4c0 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:716
 slab_alloc_node mm/slub.c:3451 [inline]
 kmem_cache_alloc_node+0x535/0xa30 mm/slub.c:3496
 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:568
 __alloc_skb+0x318/0x740 net/core/skbuff.c:654
 alloc_skb include/linux/skbuff.h:1288 [inline]
 alloc_skb_with_frags+0xbd/0xbb0 net/core/skbuff.c:6380
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2729
 tun_alloc_skb drivers/net/tun.c:1529 [inline]
 tun_get_user+0x2329/0x6920 drivers/net/tun.c:1841
 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2043
 call_write_iter include/linux/fs.h:1868 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8f9/0x1490 fs/read_write.c:584
 ksys_write+0x20f/0x4c0 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

CPU: 1 PID: 5067 Comm: syz-executor.0 Not tainted 6.4.0-rc4-syzkaller-g2741f1b02117 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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