================================================================== BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987 Read of size 16 at addr ffff8800b2f45db0 by task syz-executor.1/17575 CPU: 1 PID: 17575 Comm: syz-executor.1 Not tainted 4.4.174+ #17 0000000000000000 f7dc6ae28a351459 ffff8800b4b06e20 ffffffff81aad1a1 0000000000000000 ffffea0002cbd100 ffff8800b2f45db0 0000000000000010 ffff8800b2f45b00 ffff8800b4b06e58 ffffffff81490120 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] print_address_description+0x6f/0x21b mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report mm/kasan/report.c:408 [inline] [] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393 [] __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:439 [] ip6_tnl_xmit2+0x1f95/0x2320 net/ipv6/ip6_tunnel.c:987 [] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline] [] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212 [] __netdev_start_xmit include/linux/netdevice.h:3750 [inline] [] netdev_start_xmit include/linux/netdevice.h:3759 [inline] [] xmit_one net/core/dev.c:2781 [inline] [] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797 [] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229 [] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263 [] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369 [] dst_neigh_output include/net/dst.h:461 [inline] [] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213 [] ip_do_fragment+0x187c/0x1f70 net/ipv4/ip_output.c:635 [] ip_fragment.constprop.0+0x14b/0x200 net/ipv4/ip_output.c:505 [] ip_finish_output+0x3b9/0xc60 net/ipv4/ip_output.c:286 [] NF_HOOK_COND include/linux/netfilter.h:240 [inline] [] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362 [] dst_output include/net/dst.h:498 [inline] [] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119 [] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453 [] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842 [] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072 [] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173 [] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbe/0x110 net/socket.c:648 [] SYSC_sendto net/socket.c:1678 [inline] [] SyS_sendto+0x201/0x340 net/socket.c:1646 [] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] [] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397 [] sysenter_flags_fixed+0xd/0x1a Allocated by task 17575: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616 [] kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601 [] __kmalloc+0x141/0x330 mm/slub.c:3613 [] kmalloc include/linux/slab.h:481 [inline] [] kzalloc include/linux/slab.h:620 [inline] [] neigh_alloc net/core/neighbour.c:285 [inline] [] __neigh_create+0x1d6/0x1b30 net/core/neighbour.c:457 [] neigh_create include/net/neighbour.h:313 [inline] [] ipv4_neigh_lookup+0x52e/0x6e0 net/ipv4/route.c:464 [] dst_neigh_lookup include/net/dst.h:466 [inline] [] ip6_tnl_xmit2+0x27b/0x2320 net/ipv6/ip6_tunnel.c:982 [] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline] [] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212 [] __netdev_start_xmit include/linux/netdevice.h:3750 [inline] [] netdev_start_xmit include/linux/netdevice.h:3759 [inline] [] xmit_one net/core/dev.c:2781 [inline] [] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797 [] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229 [] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263 [] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369 [] dst_neigh_output include/net/dst.h:461 [inline] [] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213 [] ip_do_fragment+0x187c/0x1f70 net/ipv4/ip_output.c:635 [] ip_fragment.constprop.0+0x14b/0x200 net/ipv4/ip_output.c:505 [] ip_finish_output+0x3b9/0xc60 net/ipv4/ip_output.c:286 [] NF_HOOK_COND include/linux/netfilter.h:240 [inline] [] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362 [] dst_output include/net/dst.h:498 [inline] [] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119 [] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453 [] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842 [] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072 [] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173 [] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbe/0x110 net/socket.c:648 [] SYSC_sendto net/socket.c:1678 [inline] [] SyS_sendto+0x201/0x340 net/socket.c:1646 [] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] [] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397 [] sysenter_flags_fixed+0xd/0x1a Freed by task 578: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kfree+0xf4/0x310 mm/slub.c:3749 [] skb_free_head net/core/skbuff.c:571 [inline] [] skb_release_data+0x2e6/0x380 net/core/skbuff.c:602 [] skb_release_all+0x4d/0x60 net/core/skbuff.c:661 [] __kfree_skb net/core/skbuff.c:675 [inline] [] kfree_skb+0xf7/0x400 net/core/skbuff.c:696 [] netlink_unicast_kernel net/netlink/af_netlink.c:1280 [inline] [] netlink_unicast+0x630/0x700 net/netlink/af_netlink.c:1303 [] netlink_sendmsg+0x6b6/0xc80 net/netlink/af_netlink.c:1859 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbe/0x110 net/socket.c:648 [] ___sys_sendmsg+0x769/0x890 net/socket.c:1975 [] __sys_sendmsg+0xc5/0x160 net/socket.c:2009 [] SYSC_sendmsg net/socket.c:2020 [inline] [] SyS_sendmsg+0x2d/0x50 net/socket.c:2016 [] entry_SYSCALL_64_fastpath+0x1e/0x9a The buggy address belongs to the object at ffff8800b2f45b00 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 688 bytes inside of 1024-byte region [ffff8800b2f45b00, ffff8800b2f45f00) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access[ 325.848661] ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2121 at kernel/sched/core.c:7941 __might_sleep+0x138/0x1a0 kernel/sched/core.c:7941() do not call blocking ops when !TASK_RUNNING; state=1 set at [] do_wait+0x265/0xa00 kernel/exit.c:1511