=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:169 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x420/0x1d00 lib/iov_iter.c:536
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 copyout lib/iov_iter.c:169 [inline]
 _copy_to_iter+0x420/0x1d00 lib/iov_iter.c:536
 copy_to_iter include/linux/uio.h:206 [inline]
 simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:513
 __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419
 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:527
 tun_put_user drivers/net/tun.c:2159 [inline]
 tun_do_read+0x2167/0x2ae0 drivers/net/tun.c:2238
 tun_chr_read_iter+0x3f0/0x670 drivers/net/tun.c:2262
 call_read_iter include/linux/fs.h:1862 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x933/0xe40 fs/read_write.c:470
 ksys_read+0x20f/0x4c0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x93/0xd0 fs/read_write.c:621
 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 stored to memory at:
 pskb_expand_head+0x305/0x1a10 net/core/skbuff.c:2062
 __skb_cow include/linux/skbuff.h:3589 [inline]
 skb_cow_head include/linux/skbuff.h:3623 [inline]
 ip_tunnel_xmit+0x36ef/0x3e80 net/ipv4/ip_tunnel.c:824
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 erspan_xmit+0x13da/0x1f00 net/ipv4/ip_gre.c:715
 __netdev_start_xmit include/linux/netdevice.h:4918 [inline]
 netdev_start_xmit include/linux/netdevice.h:4932 [inline]
 xmit_one net/core/dev.c:3578 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3594
 sch_direct_xmit+0x3c5/0xd40 net/sched/sch_generic.c:342
 __dev_xmit_skb net/core/dev.c:3805 [inline]
 __dev_queue_xmit+0x2f1c/0x50f0 net/core/dev.c:4210
 dev_queue_xmit include/linux/netdevice.h:3088 [inline]
 neigh_resolve_output+0x99a/0xab0 net/core/neighbour.c:1552
 neigh_output include/net/neighbour.h:544 [inline]
 ip_finish_output2+0x1807/0x1a10 net/ipv4/ip_output.c:229
 __ip_finish_output+0x266/0x720
 ip_finish_output+0x4b/0x420 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:292 [inline]
 ip_output+0x1f3/0x4e0 net/ipv4/ip_output.c:431
 dst_output include/net/dst.h:458 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0x110/0x2a0 net/ipv4/ip_output.c:1597
 udp_send_skb+0xfd0/0x1ad0 net/ipv4/udp.c:978
 udp_sendmsg+0x2e43/0x3180 net/ipv4/udp.c:1265
 udpv6_sendmsg+0x1379/0x4000 net/ipv6/udp.c:1401
 inet6_sendmsg+0x105/0x190 net/ipv6/af_inet6.c:651
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x999/0xd50 net/socket.c:2503
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2557
 __sys_sendmmsg+0x3c1/0x950 net/socket.c:2643
 __do_sys_sendmmsg net/socket.c:2672 [inline]
 __se_sys_sendmmsg net/socket.c:2669 [inline]
 __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2669
 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
 sock_alloc_send_skb include/net/sock.h:1872 [inline]
 __ip_append_data+0x4343/0x6290 net/ipv4/ip_output.c:1121
 ip_make_skb+0x1ce/0x610 net/ipv4/ip_output.c:1663
 udp_sendmsg+0x2d13/0x3180 net/ipv4/udp.c:1260
 udpv6_sendmsg+0x1379/0x4000 net/ipv6/udp.c:1401
 inet6_sendmsg+0x105/0x190 net/ipv6/af_inet6.c:651
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x999/0xd50 net/socket.c:2503
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2557
 __sys_sendmmsg+0x3c1/0x950 net/socket.c:2643
 __do_sys_sendmmsg net/socket.c:2672 [inline]
 __se_sys_sendmmsg net/socket.c:2669 [inline]
 __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2669
 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

Bytes 38-41 of 92 are uninitialized
Memory access of size 92 starts at ffff888124ae78c0
Data copied to user address 00007f1c7c6cf980

CPU: 0 PID: 15139 Comm: syz-executor.2 Tainted: G        W          6.4.0-rc7-syzkaller-ge6bc8833d80f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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