IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready ================================================================== BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x1838/0x1b80 net/ipv6/ip6_output.c:254 Read of size 8 at addr ffff8801d3e9c298 by task syz-executor2/10058 CPU: 1 PID: 10058 Comm: syz-executor2 Not tainted 4.9.124-g09eb2ba #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d7b3f540 ffffffff81eb95e9 ffffea00074fa700 ffff8801d3e9c298 0000000000000000 ffff8801d3e9c298 0000000000000040 ffff8801d7b3f578 ffffffff8156c35e ffff8801d3e9c298 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] ip6_dst_idev include/net/ip6_fib.h:141 [inline] [] ip6_xmit+0x1838/0x1b80 net/ipv6/ip6_output.c:254 [] inet6_csk_xmit+0x27c/0x4d0 net/ipv6/inet6_connection_sock.c:178 [] l2tp_xmit_core net/l2tp/l2tp_core.c:1178 [inline] [] l2tp_xmit_skb+0xc45/0xf30 net/l2tp/l2tp_core.c:1273 [] pppol2tp_sendmsg+0x4e0/0x790 net/l2tp/l2tp_ppp.c:339 [] sock_sendmsg_nosec net/socket.c:648 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:658 [] ___sys_sendmsg+0x47a/0x840 net/socket.c:1982 [] __sys_sendmmsg+0x161/0x3d0 net/socket.c:2072 [] SYSC_sendmmsg net/socket.c:2103 [inline] [] SyS_sendmmsg+0x35/0x60 net/socket.c:2098 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 8362: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xbe/0x290 mm/slub.c:2728 dst_alloc+0xb5/0x1a0 net/core/dst.c:210 rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1486 __mkroute_output net/ipv4/route.c:2145 [inline] __ip_route_output_key_hash+0x9ac/0x23c0 net/ipv4/route.c:2355 __ip_route_output_key include/net/route.h:123 [inline] ip_route_output_flow+0x29/0xa0 net/ipv4/route.c:2442 ip_route_output_key include/net/route.h:133 [inline] ip_tunnel_xmit+0x5fa/0x3270 net/ipv4/ip_tunnel.c:716 ipip_tunnel_xmit+0x1b7/0x200 net/ipv4/ipip.c:308 __netdev_start_xmit include/linux/netdevice.h:4062 [inline] netdev_start_xmit include/linux/netdevice.h:4071 [inline] xmit_one net/core/dev.c:2955 [inline] dev_hard_start_xmit+0x197/0x8b0 net/core/dev.c:2971 __dev_queue_xmit+0x19a5/0x2080 net/core/dev.c:3451 dev_queue_xmit+0x17/0x20 net/core/dev.c:3484 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1362 dst_neigh_output include/net/dst.h:470 [inline] ip_finish_output2+0x6ab/0x1110 net/ipv4/ip_output.c:225 ip_do_fragment+0x19a0/0x2160 net/ipv4/ip_output.c:671 ip_fragment.constprop.57+0x143/0x200 net/ipv4/ip_output.c:544 ip_finish_output+0x6bb/0xb00 net/ipv4/ip_output.c:311 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1cd/0x550 net/ipv4/ip_output.c:401 dst_output include/net/dst.h:507 [inline] ip_local_out+0x9b/0x180 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1489 udp_send_skb+0x5b5/0xc50 net/ipv4/udp.c:833 udp_push_pending_frames+0x4e/0xe0 net/ipv4/udp.c:861 udp_sendmsg+0x1097/0x1c50 net/ipv4/udp.c:1089 udpv6_sendmsg+0x1cfe/0x2430 net/ipv6/udp.c:1091 inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770 sock_sendmsg_nosec net/socket.c:648 [inline] sock_sendmsg+0xcc/0x110 net/socket.c:658 SYSC_sendto+0x21c/0x370 net/socket.c:1683 SyS_sendto+0x40/0x50 net/socket.c:1651 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 8357: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 dst_destroy+0x200/0x360 net/core/dst.c:270 dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 __rcu_reclaim kernel/rcu/rcu.h:118 [inline] rcu_do_batch kernel/rcu/tree.c:2789 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037 __do_softirq+0x210/0x940 kernel/softirq.c:288 The buggy address belongs to the object at ffff8801d3e9c280 which belongs to the cache ip_dst_cache of size 216 The buggy address is located 24 bytes inside of 216-byte region [ffff8801d3e9c280, ffff8801d3e9c358) The buggy address belongs to the page: page:ffffea00074fa700 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x8000000000000080(slab) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d3e9c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801d3e9c200: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d3e9c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d3e9c300: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff8801d3e9c380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================