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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 ffff8880947dc8bf by task syz-executor.2/26440

CPU: 0 PID: 26440 Comm: syz-executor.2 Not tainted 5.2.0-rc2+ #10
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_flow+0xa8/0x220 net/ipv6/ip6_output.c:1155
 ip6_datagram_dst_update+0x5d8/0xc20 net/ipv6/datagram.c:91
 ip6_datagram_release_cb net/ipv6/datagram.c:132 [inline]
 ip6_datagram_release_cb+0x4ed/0x550 net/ipv6/datagram.c:116
 release_sock+0xba/0x1c0 net/core/sock.c:2940
 udpv6_destroy_sock+0x29/0x150 net/ipv6/udp.c:1546
 sk_common_release+0x6b/0x330 net/core/sock.c:3151
 udp_lib_close+0x16/0x20 include/net/udp.h:206
 inet_release+0xe0/0x1f0 net/ipv4/af_inet.c:431
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:474
 __sock_release+0xce/0x2a0 net/socket.c:607
 sock_close+0x1b/0x30 net/socket.c:1279
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x412f61
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffcaece7760 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000412f61
RDX: 0000001b2c020000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 000000007b5fd88f R09: 000000007b5fd893
R10: 00007ffcaece7840 R11: 0000000000000293 R12: 000000000075c920
R13: 000000000075c920 R14: 000000000007e8e4 R15: 000000000075bfcc

Allocated by task 12122:
 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
 ip6_rt_pcpu_alloc net/ipv6/route.c:1257 [inline]
 rt6_make_pcpu_route net/ipv6/route.c:1287 [inline]
 ip6_pol_route+0x649/0x1010 net/ipv6/route.c:2031
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2204
 __fib6_rule_action net/ipv6/fib6_rules.c:230 [inline]
 fib6_rule_action+0x49c/0xb40 net/ipv6/fib6_rules.c:261
 fib_rules_lookup+0x34c/0xa90 net/core/fib_rules.c:304
 fib6_rule_lookup+0x384/0x5a0 net/ipv6/fib6_rules.c:108
 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2233
 ip6_route_output include/net/ip6_route.h:89 [inline]
 icmpv6_xrlim_allow+0x11e/0x440 net/ipv6/icmp.c:212
 icmp6_send+0x1107/0x1e50 net/ipv6/icmp.c:540
 icmpv6_send+0xec/0x230 net/ipv6/ip6_icmp.c:43
 ip6_link_failure+0x2b/0x530 net/ipv6/route.c:2367
 dst_link_failure include/net/dst.h:416 [inline]
 ip6_tnl_xmit+0x444/0x34f0 net/ipv6/ip6_tunnel.c:1227
 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1383 [inline]
 ip6_tnl_start_xmit+0x867/0x1ce0 net/ipv6/ip6_tunnel.c:1409
 __netdev_start_xmit include/linux/netdevice.h:4410 [inline]
 netdev_start_xmit include/linux/netdevice.h:4424 [inline]
 xmit_one net/core/dev.c:3292 [inline]
 dev_hard_start_xmit+0x18a/0x950 net/core/dev.c:3308
 __dev_queue_xmit+0x2a8e/0x36b0 net/core/dev.c:3881
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3914
 neigh_direct_output+0x16/0x20 net/core/neighbour.c:1532
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x1034/0x2550 net/ipv6/ip6_output.c:120
 __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]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_xmit+0xe35/0x20b0 net/ipv6/ip6_output.c:283
 sctp_v6_xmit+0x313/0x660 net/sctp/ipv6.c:217
 sctp_packet_transmit+0x1ba5/0x36c0 net/sctp/output.c:626
 sctp_packet_singleton net/sctp/outqueue.c:772 [inline]
 sctp_outq_flush_ctrl.constprop.0+0x73c/0xd30 net/sctp/outqueue.c:903
 sctp_outq_flush+0xe8/0x2780 net/sctp/outqueue.c:1185
 sctp_outq_uncork+0x6c/0x80 net/sctp/outqueue.c:757
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1776 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline]
 sctp_do_sm+0x504/0x50e0 net/sctp/sm_sideeffect.c:1150
 sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:73
 __sctp_connect+0x8c3/0xcd0 net/sctp/socket.c:1211
 sctp_connect net/sctp/socket.c:4846 [inline]
 sctp_inet_connect+0x29c/0x340 net/sctp/socket.c:4862
 __sys_connect+0x264/0x330 net/socket.c:1840
 __do_sys_connect net/socket.c:1851 [inline]
 __se_sys_connect net/socket.c:1848 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1848
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 10391:
 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 ffff8880947dc780
 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 [ffff8880947dc780, ffff8880947dc860)
The buggy address belongs to the page:
page:ffffea000251f700 refcount:1 mapcount:0 mapping:ffff88809bece500 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00023baf48 ffff88809b160f48 ffff88809bece500
raw: 0000000000000000 ffff8880947dc000 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880947dc780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880947dc800: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff8880947dc880: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                                        ^
 ffff8880947dc900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880947dc980: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
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