skbuff: bad partial csum: csum=53081/14726 len=2273 ================================================================== BUG: KASAN: use-after-free in ipv6_get_dsfield include/net/dsfield.h:23 [inline] BUG: KASAN: use-after-free in ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline] BUG: KASAN: use-after-free in sit_tunnel_xmit+0x2a41/0x3130 net/ipv6/sit.c:1016 Read of size 2 at addr ffff8801c64afd00 by task syz-executor3/16942 CPU: 0 PID: 16942 Comm: syz-executor3 Not tainted 4.14.0-rc5+ #97 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428 ipv6_get_dsfield include/net/dsfield.h:23 [inline] ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline] sit_tunnel_xmit+0x2a41/0x3130 net/ipv6/sit.c:1016 __netdev_start_xmit include/linux/netdevice.h:4022 [inline] netdev_start_xmit include/linux/netdevice.h:4031 [inline] xmit_one net/core/dev.c:3008 [inline] dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 __dev_queue_xmit+0x17d2/0x2070 net/core/dev.c:3505 dev_queue_xmit+0x17/0x20 net/core/dev.c:3538 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1390 neigh_output include/net/neighbour.h:481 [inline] ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120 ip6_fragment+0x25ae/0x3420 net/ipv6/ip6_output.c:723 ip6_finish_output+0x319/0x920 net/ipv6/ip6_output.c:144 NF_HOOK_COND include/linux/netfilter.h:238 [inline] ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163 dst_output include/net/dst.h:459 [inline] ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176 ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1658 ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1678 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] rawv6_sendmsg+0x2eb9/0x3e40 net/ipv6/raw.c:935 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x452869 RSP: 002b:00007fe3c12e5be8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452869 RDX: 00000000000007f1 RSI: 000000002013b7ff RDI: 0000000000000014 RBP: 0000000000000161 R08: 00000000204e8fe4 R09: 000000000000001c R10: 0000000001000000 R11: 0000000000000212 R12: 00000000006f01b8 R13: 00000000ffffffff R14: 00007fe3c12e66d4 R15: 0000000000000017 Allocated by task 16924: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3703 __kmalloc_reserve.isra.40+0x41/0xd0 net/core/skbuff.c:138 __alloc_skb+0x13b/0x780 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:985 [inline] sock_wmalloc+0x140/0x1d0 net/core/sock.c:1932 __ip6_append_data.isra.43+0x2681/0x3340 net/ipv6/ip6_output.c:1397 ip6_append_data+0x189/0x290 net/ipv6/ip6_output.c:1552 rawv6_sendmsg+0x1dd9/0x3e40 net/ipv6/raw.c:928 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 16942: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 skb_free_head+0x74/0xb0 net/core/skbuff.c:554 pskb_expand_head+0x36b/0x1210 net/core/skbuff.c:1494 __pskb_pull_tail+0x14a/0x17c0 net/core/skbuff.c:1877 pskb_may_pull include/linux/skbuff.h:2102 [inline] _decode_session6+0x8a4/0x1100 net/ipv6/xfrm6_policy.c:148 __xfrm_decode_session+0x63/0x100 net/xfrm/xfrm_policy.c:2343 xfrm_decode_session_reverse include/net/xfrm.h:1181 [inline] icmpv6_route_lookup+0x343/0x640 net/ipv6/icmp.c:372 icmp6_send+0x1569/0x25b0 net/ipv6/icmp.c:551 icmpv6_send+0x142/0x280 net/ipv6/ip6_icmp.c:42 ip6_link_failure+0x94/0x580 net/ipv6/route.c:1997 dst_link_failure include/net/dst.h:442 [inline] ipip6_tunnel_xmit net/ipv6/sit.c:940 [inline] sit_tunnel_xmit+0x244f/0x3130 net/ipv6/sit.c:1016 __netdev_start_xmit include/linux/netdevice.h:4022 [inline] netdev_start_xmit include/linux/netdevice.h:4031 [inline] xmit_one net/core/dev.c:3008 [inline] dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 __dev_queue_xmit+0x17d2/0x2070 net/core/dev.c:3505 dev_queue_xmit+0x17/0x20 net/core/dev.c:3538 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1390 neigh_output include/net/neighbour.h:481 [inline] ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120 ip6_fragment+0x25ae/0x3420 net/ipv6/ip6_output.c:723 ip6_finish_output+0x319/0x920 net/ipv6/ip6_output.c:144 NF_HOOK_COND include/linux/netfilter.h:238 [inline] ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163 dst_output include/net/dst.h:459 [inline] ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176 ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1658 ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1678 rawv6_push_pending_frames net/ipv6/raw.c:616 [inline] rawv6_sendmsg+0x2eb9/0x3e40 net/ipv6/raw.c:935 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x352/0x5a0 net/socket.c:1750 SyS_sendto+0x40/0x50 net/socket.c:1718 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801c64afc80 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 128 bytes inside of 512-byte region [ffff8801c64afc80, ffff8801c64afe80) The buggy address belongs to the page: page:ffffea0007192bc0 count:1 mapcount:0 mapping:ffff8801c64af000 index:0x0 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801c64af000 0000000000000000 0000000100000006 raw: ffffea00072d04e0 ffffea0007083fe0 ffff8801dac00940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c64afc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c64afc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c64afd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c64afd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c64afe00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================