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BUG: KASAN: slab-out-of-bounds in ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1010
Read of size 8 at addr ffff8880920349ff by task syz-executor.4/15575

CPU: 1 PID: 15575 Comm: syz-executor.4 Not tainted 5.2.0-rc1+ #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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:1010
 ip6_dst_lookup+0x4d/0x70 net/ipv6/ip6_output.c:1073
 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
 udpv6_rcv+0x22/0x30 net/ipv6/udp.c:1027
 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:4990
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5104
 process_backlog+0x206/0x750 net/core/dev.c:5944
 napi_poll net/core/dev.c:6367 [inline]
 net_rx_action+0x4f5/0x1070 net/core/dev.c:6433
 __do_softirq+0x25c/0x94c kernel/softirq.c:293
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1040
 </IRQ>
 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+0x56d/0xc20 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:171
 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:1735
 udp_v6_send_skb.isra.0+0x839/0x14f0 net/ipv6/udp.c:1180
 udp_v6_push_pending_frames+0x295/0x3b0 net/ipv6/udp.c:1213
 udp_lib_setsockopt+0x73c/0x9a0 net/ipv4/udp.c:2525
 udpv6_setsockopt net/ipv6/udp.c:1569 [inline]
 udpv6_setsockopt+0x9e/0xb0 net/ipv6/udp.c:1565
 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3130
 __sys_setsockopt+0x17a/0x280 net/socket.c:2078
 __do_sys_setsockopt net/socket.c:2089 [inline]
 __se_sys_setsockopt net/socket.c:2086 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2086
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459279
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:00007fa4cd751c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459279
RDX: 0000000000000001 RSI: 0000000000000011 RDI: 0000000000000003
RBP: 000000000075c100 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00007fa4cd7526d4
R13: 00000000004c74bd R14: 00000000004dc948 R15: 00000000ffffffff

Allocated by task 9856:
 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+0x656/0x1050 net/ipv6/route.c:2031
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2204
 fib6_rule_lookup+0x279/0x5a0 net/ipv6/fib6_rules.c:120
 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2233
 ip6_route_output include/net/ip6_route.h:89 [inline]
 ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:966
 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1094
 ip6_datagram_dst_update+0x5d8/0xc20 net/ipv6/datagram.c:91
 __ip6_datagram_connect+0x5e9/0x1390 net/ipv6/datagram.c:250
 ip6_datagram_connect+0x30/0x50 net/ipv6/datagram.c:273
 inet_dgram_connect+0x14a/0x2d0 net/ipv4/af_inet.c:575
 __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 16:
 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 ffff8880920348c0
 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 [ffff8880920348c0, ffff8880920349a0)
The buggy address belongs to the page:
page:ffffea0002480d00 refcount:1 mapcount:0 mapping:ffff88821691acc0 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0002438408 ffffea00025f8388 ffff88821691acc0
raw: 0000000000000000 ffff888092034000 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888092034880: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff888092034900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888092034980: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff888092034a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888092034a80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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