================================================================== BUG: KASAN: slab-out-of-bounds in ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1071 Read of size 8 at addr ffff8880931b0abf by task syz-executor.0/16762 CPU: 1 PID: 16762 Comm: syz-executor.0 Not tainted 5.2.0-rc2+ #23 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1071 ip6_dst_lookup+0x4d/0x70 net/ipv6/ip6_output.c:1134 icmpv6_route_lookup+0x346/0x4d0 net/ipv6/icmp.c:377 icmp6_send+0x12b8/0x1e50 net/ipv6/icmp.c:556 icmpv6_send+0xec/0x230 net/ipv6/ip6_icmp.c:43 __udp6_lib_rcv+0x1ad1/0x2cc0 net/ipv6/udp.c:938 udplitev6_rcv+0x22/0x30 net/ipv6/udplite.c:20 ip6_protocol_deliver_rcu+0x2fe/0x16c0 net/ipv6/ip6_input.c:401 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:442 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:451 dst_input include/net/dst.h:439 [inline] ip6_rcv_finish+0x1de/0x310 net/ipv6/ip6_input.c:80 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:276 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:4985 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5099 process_backlog+0x206/0x750 net/core/dev.c:5910 napi_poll net/core/dev.c:6333 [inline] net_rx_action+0x4f5/0x1070 net/core/dev.c:6399 __do_softirq+0x25c/0x94c kernel/softirq.c:293 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1040 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:338 do_softirq kernel/softirq.c:330 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:190 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline] ip6_finish_output2+0x10a0/0x2550 net/ipv6/ip6_output.c:121 __ip6_finish_output+0x444/0xaa0 net/ipv6/ip6_output.c:146 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:156 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:179 dst_output include/net/dst.h:433 [inline] ip6_local_out+0xbb/0x1b0 net/ipv6/output_core.c:179 ip6_send_skb+0xbb/0x350 net/ipv6/ip6_output.c:1796 udp_v6_send_skb.isra.0+0x839/0x14f0 net/ipv6/udp.c:1180 udpv6_sendmsg+0x21e0/0x28d0 net/ipv6/udp.c:1477 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:802 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:671 ___sys_sendmsg+0x803/0x920 net/socket.c:2292 __sys_sendmsg+0x105/0x1d0 net/socket.c:2330 __do_sys_sendmsg net/socket.c:2339 [inline] __se_sys_sendmsg net/socket.c:2337 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2337 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4592c9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe5d2bfcc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004592c9 RDX: 0000000000000000 RSI: 0000000020000740 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe5d2bfd6d4 R13: 00000000004c6f76 R14: 00000000004dc0b0 R15: 00000000ffffffff Allocated by task 2865: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 dst_alloc+0x10e/0x200 net/core/dst.c:93 ip6_dst_alloc+0x34/0xa0 net/ipv6/route.c:356 icmp6_dst_alloc+0x1a9/0x660 net/ipv6/route.c:2806 ndisc_send_skb+0xfc1/0x14a0 net/ipv6/ndisc.c:488 ndisc_send_ns+0x3a9/0x850 net/ipv6/ndisc.c:650 addrconf_dad_work+0xb88/0x1150 net/ipv6/addrconf.c:4121 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 0: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 dst_destroy+0x29e/0x3c0 net/core/dst.c:129 dst_destroy_rcu+0x16/0x19 net/core/dst.c:142 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0xba5/0x1500 kernel/rcu/tree.c:2291 __do_softirq+0x25c/0x94c kernel/softirq.c:293 The buggy address belongs to the object at ffff8880931b0980 which belongs to the cache ip6_dst_cache of size 224 The buggy address is located 95 bytes to the right of 224-byte region [ffff8880931b0980, ffff8880931b0a60) The buggy address belongs to the page: page:ffffea00024c6c00 refcount:1 mapcount:0 mapping:ffff88809b24ab00 index:0xffff8880931b0480 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea0002831988 ffffea00022c7d88 ffff88809b24ab00 raw: ffff8880931b0480 ffff8880931b00c0 000000010000000a 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880931b0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880931b0a00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880931b0a80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ^ ffff8880931b0b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880931b0b80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================