===================================================== 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:2151 [inline] tun_do_read+0x2167/0x2ae0 drivers/net/tun.c:2230 tun_chr_read_iter+0x3f0/0x670 drivers/net/tun.c:2254 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 __pskb_pull_tail+0x13b/0x2320 net/core/skbuff.c:2613 __skb_linearize include/linux/skbuff.h:3710 [inline] skb_checksum_help+0x2bc/0x860 net/core/dev.c:3254 skb_csum_hwoffload_help net/core/dev.c:3639 [inline] validate_xmit_skb+0xf84/0x1b50 net/core/dev.c:3682 validate_xmit_skb_list+0xf4/0x2f0 net/core/dev.c:3709 sch_direct_xmit+0xd0/0xd40 net/sched/sch_generic.c:327 __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:3085 [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+0xe9/0x140 net/ipv4/ip_output.c:126 iptunnel_xmit+0x6b7/0xba0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x398d/0x3e80 net/ipv4/ip_tunnel.c:831 __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:4915 [inline] netdev_start_xmit include/linux/netdevice.h:4929 [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:3085 [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+0x2dff/0x3140 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 stored to memory at: pskb_expand_head+0x305/0x1a10 net/core/skbuff.c:2062 __skb_cow include/linux/skbuff.h:3579 [inline] skb_cow_head include/linux/skbuff.h:3613 [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:4915 [inline] netdev_start_xmit include/linux/netdevice.h:4929 [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:3085 [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+0x2dff/0x3140 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 skb_segment+0x1be4/0x7020 net/core/skbuff.c:4516 __udp_gso_segment+0x391/0x33f0 net/ipv4/udp_offload.c:290 udp4_ufo_fragment+0xb24/0xb80 net/ipv4/udp_offload.c:392 inet_gso_segment+0xd1e/0x1e10 net/ipv4/af_inet.c:1396 skb_mac_gso_segment+0x3e8/0x760 net/core/gro.c:141 __skb_gso_segment+0x4b3/0x740 net/core/dev.c:3401 skb_gso_segment include/linux/netdevice.h:4859 [inline] validate_xmit_skb+0x110d/0x1b50 net/core/dev.c:3659 validate_xmit_skb_list+0xf4/0x2f0 net/core/dev.c:3709 sch_direct_xmit+0xd0/0xd40 net/sched/sch_generic.c:327 __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:3085 [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+0x2dff/0x3140 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 Bytes 38-41 of 832 are uninitialized Memory access of size 832 starts at ffff888012c408c0 Data copied to user address 00007f96faccf980 CPU: 0 PID: 22165 Comm: syz-executor.3 Not tainted 6.4.0-rc2-syzkaller-gdad188c049f8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 =====================================================