protocol 86dd is buggy, dev ip6tnl1 ================================================================== BUG: KASAN: slab-out-of-bounds in ip6_tnl_parse_tlv_enc_lim+0x4b7/0x550 net/ipv6/ip6_tunnel.c:449 Read of size 1 at addr ffff8801c6795607 by task syz-executor1/27061 CPU: 0 PID: 27061 Comm: syz-executor1 Not tainted 4.14.78+ #24 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 print_address_description+0x60/0x22b mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409 ip6_tnl_parse_tlv_enc_lim+0x4b7/0x550 net/ipv6/ip6_tunnel.c:449 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1339 [inline] ip6_tnl_start_xmit+0xfe5/0x1aa0 net/ipv6/ip6_tunnel.c:1403 __netdev_start_xmit include/linux/netdevice.h:4030 [inline] netdev_start_xmit include/linux/netdevice.h:4039 [inline] xmit_one net/core/dev.c:3009 [inline] dev_hard_start_xmit+0x191/0x890 net/core/dev.c:3025 __dev_queue_xmit+0x13d9/0x1f40 net/core/dev.c:3525 __bpf_tx_skb net/core/filter.c:1708 [inline] __bpf_redirect_common net/core/filter.c:1746 [inline] __bpf_redirect+0x5b0/0x990 net/core/filter.c:1753 ____bpf_clone_redirect net/core/filter.c:1786 [inline] bpf_clone_redirect+0x1d4/0x2b0 net/core/filter.c:1758 ___bpf_prog_run+0x248e/0x5c70 kernel/bpf/core.c:1012 Allocated by task 27061: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x4f/0xd0 mm/kasan/kasan.c:551 __kmalloc+0x153/0x340 mm/slub.c:3760 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] bpf_test_init.isra.1+0x52/0xc0 net/bpf/test_run.c:81 bpf_prog_test_run_skb+0xfb/0x8c0 net/bpf/test_run.c:103 bpf_prog_test_run kernel/bpf/syscall.c:1330 [inline] SYSC_bpf kernel/bpf/syscall.c:1602 [inline] SyS_bpf+0x79d/0x3640 kernel/bpf/syscall.c:1547 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8801c6795400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 7 bytes to the right of 512-byte region [ffff8801c6795400, ffff8801c6795600) The buggy address belongs to the page: page:ffffea000719e500 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001800c000c raw: dead000000000100 dead000000000200 ffff8801da802c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c6795500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c6795580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8801c6795600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801c6795680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c6795700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================