dccp_v4_rcv: dropped packet with invalid checksum ================================================================== BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:143 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576 CPU: 1 PID: 12071 Comm: syz-executor0 Not tainted 4.20.0-rc3+ #97 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x32d/0x480 lib/dump_stack.c:113 kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:682 kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:742 kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634 copyout lib/iov_iter.c:143 [inline] _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576 copy_to_iter include/linux/uio.h:143 [inline] skb_copy_datagram_iter+0x4e2/0x1070 net/core/datagram.c:431 tun_put_user drivers/net/tun.c:2115 [inline] tun_do_read+0x2568/0x2de0 drivers/net/tun.c:2199 tun_chr_read_iter+0x232/0x490 drivers/net/tun.c:2218 call_read_iter include/linux/fs.h:1851 [inline] new_sync_read fs/read_write.c:406 [inline] __vfs_read+0x874/0xb00 fs/read_write.c:418 vfs_read+0x380/0x6b0 fs/read_write.c:452 ksys_read fs/read_write.c:578 [inline] __do_sys_read fs/read_write.c:588 [inline] __se_sys_read+0x17a/0x370 fs/read_write.c:586 __x64_sys_read+0x4a/0x70 fs/read_write.c:586 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 dccp_v4_rcv: dropped packet with invalid checksum entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x410fa0 Code: 01 f0 ff ff 0f 83 c0 19 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 0d 50 63 00 00 75 14 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 94 19 00 00 c3 48 83 ec 08 e8 6a fc ff ff RSP: 002b:0000000000a3f988 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410fa0 RDX: 00000000000003e8 RSI: 0000000000a3f9a0 RDI: 00000000000000f0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000004 R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000008d R15: 0000000000000000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:245 [inline] kmsan_save_stack mm/kmsan/kmsan.c:260 [inline] kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:468 kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:343 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:361 __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:148 pskb_expand_head+0x436/0x1d20 net/core/skbuff.c:1470 __skb_cow include/linux/skbuff.h:2948 [inline] skb_cow_head include/linux/skbuff.h:2982 [inline] ip_tunnel_xmit+0x35a3/0x3d90 net/ipv4/ip_tunnel.c:780 __gre_xmit net/ipv4/ip_gre.c:451 [inline] erspan_xmit+0x1bce/0x35d0 net/ipv4/ip_gre.c:749 __netdev_start_xmit include/linux/netdevice.h:4356 [inline] netdev_start_xmit include/linux/netdevice.h:4365 [inline] xmit_one net/core/dev.c:3252 [inline] dev_hard_start_xmit+0x6dc/0xde0 net/core/dev.c:3268 sch_direct_xmit+0x59b/0x890 net/sched/sch_generic.c:327 qdisc_restart net/sched/sch_generic.c:390 [inline] __qdisc_run+0x1bac/0x3600 net/sched/sch_generic.c:398 qdisc_run include/net/pkt_sched.h:121 [inline] __dev_xmit_skb net/core/dev.c:3447 [inline] __dev_queue_xmit+0x2131/0x3e00 net/core/dev.c:3806 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3871 neigh_resolve_output+0xab7/0xb50 net/core/neighbour.c:1382 neigh_output include/net/neighbour.h:484 [inline] ip_finish_output2+0x141a/0x1560 net/ipv4/ip_output.c:229 ip_finish_output+0xd93/0x10f0 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x55c/0x630 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out net/ipv4/ip_output.c:124 [inline] ip_send_skb+0x178/0x370 net/ipv4/ip_output.c:1441 udp_send_skb+0x1439/0x1920 net/ipv4/udp.c:829 udp_push_pending_frames net/ipv4/udp.c:857 [inline] udp_sendmsg+0x1496/0x4350 net/ipv4/udp.c:1148 udpv6_sendmsg+0x123e/0x4960 net/ipv6/udp.c:1203 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xdbc/0x11d0 net/socket.c:2116 __sys_sendmmsg+0x56b/0xa90 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2237 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2237 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:245 [inline] kmsan_save_stack mm/kmsan/kmsan.c:260 [inline] kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:468 kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:343 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:361 __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:148 pskb_expand_head+0x436/0x1d20 net/core/skbuff.c:1470 __skb_cow include/linux/skbuff.h:2948 [inline] skb_cow_head include/linux/skbuff.h:2982 [inline] erspan_xmit+0x618/0x35d0 net/ipv4/ip_gre.c:728 __netdev_start_xmit include/linux/netdevice.h:4356 [inline] netdev_start_xmit include/linux/netdevice.h:4365 [inline] xmit_one net/core/dev.c:3252 [inline] dev_hard_start_xmit+0x6dc/0xde0 net/core/dev.c:3268 sch_direct_xmit+0x59b/0x890 net/sched/sch_generic.c:327 qdisc_restart net/sched/sch_generic.c:390 [inline] __qdisc_run+0x1bac/0x3600 net/sched/sch_generic.c:398 qdisc_run include/net/pkt_sched.h:121 [inline] __dev_xmit_skb net/core/dev.c:3447 [inline] __dev_queue_xmit+0x2131/0x3e00 net/core/dev.c:3806 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3871 neigh_resolve_output+0xab7/0xb50 net/core/neighbour.c:1382 neigh_output include/net/neighbour.h:484 [inline] ip_finish_output2+0x141a/0x1560 net/ipv4/ip_output.c:229 ip_finish_output+0xd93/0x10f0 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x55c/0x630 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out net/ipv4/ip_output.c:124 [inline] ip_send_skb+0x178/0x370 net/ipv4/ip_output.c:1441 udp_send_skb+0x1439/0x1920 net/ipv4/udp.c:829 udp_push_pending_frames net/ipv4/udp.c:857 [inline] udp_sendmsg+0x1496/0x4350 net/ipv4/udp.c:1148 udpv6_sendmsg+0x123e/0x4960 net/ipv6/udp.c:1203 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xdbc/0x11d0 net/socket.c:2116 __sys_sendmmsg+0x56b/0xa90 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2237 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2237 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:245 [inline] kmsan_internal_poison_shadow+0x6d/0x130 mm/kmsan/kmsan.c:169 kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:195 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2758 [inline] __kmalloc_node_track_caller+0xf62/0x14e0 mm/slub.c:4387 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x42b/0xeb0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:998 [inline] alloc_skb_with_frags+0x1c9/0xa80 net/core/skbuff.c:5220 sock_alloc_send_pskb+0xeb3/0x14c0 net/core/sock.c:2083 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2100 __ip_append_data+0x2bd2/0x4460 net/ipv4/ip_output.c:981 ip_append_data+0x30c/0x450 net/ipv4/ip_output.c:1196 udp_sendmsg+0x74e/0x4350 net/ipv4/udp.c:1142 udpv6_sendmsg+0x123e/0x4960 net/ipv6/udp.c:1203 inet_sendmsg+0x4e9/0x800 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] __sys_sendto+0x8d5/0xae0 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto+0x107/0x130 net/socket.c:1796 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 Bytes 38-41 of 92 are uninitialized Memory access of size 92 starts at ffff888160b350a0 Data copied to user address 0000000000a3f9a0 ==================================================================