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BUG: KASAN: slab-out-of-bounds in _decode_session6+0xf56/0x1370 net/ipv6/xfrm6_policy.c:137
Read of size 1 at addr ffff8880aa6a5c02 by task syz-fuzzer/8069

CPU: 1 PID: 8069 Comm: syz-fuzzer Not tainted 4.19.211-syzkaller #0
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+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430
 _decode_session6+0xf56/0x1370 net/ipv6/xfrm6_policy.c:137
 __xfrm_decode_session+0x5a/0x130 net/xfrm/xfrm_policy.c:2299
 xfrm_decode_session include/net/xfrm.h:1238 [inline]
 vti6_tnl_xmit+0x42b/0x1c80 net/ipv6/ip6_vti.c:569
 __netdev_start_xmit include/linux/netdevice.h:4349 [inline]
 netdev_start_xmit include/linux/netdevice.h:4363 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
 sch_direct_xmit+0x2d6/0xf70 net/sched/sch_generic.c:332
 qdisc_restart net/sched/sch_generic.c:395 [inline]
 __qdisc_run+0x4d0/0x1640 net/sched/sch_generic.c:403
 __dev_xmit_skb net/core/dev.c:3500 [inline]
 __dev_queue_xmit+0x1518/0x2e00 net/core/dev.c:3807
 neigh_output include/net/neighbour.h:501 [inline]
 ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209
 dst_output include/net/dst.h:455 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ndisc_send_skb+0xa24/0x1720 net/ipv6/ndisc.c:491
 ndisc_send_rs+0x131/0x690 net/ipv6/ndisc.c:685
 addrconf_rs_timer+0x384/0x6a0 net/ipv6/addrconf.c:3835
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1696 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1098
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0033:0x420e35
Code: 48 8b 5c 24 78 89 ce 4c 8b 44 24 70 4c 8b 8c 24 90 00 00 00 4c 8b 94 24 98 00 00 00 4c 8b 5c 24 58 e9 32 ff ff ff 48 89 04 24 <48> 8b 84 24 90 00 00 00 48 89 44 24 08 48 8b 5c 24 58 48 89 5c 24
RSP: 002b:000000c000039ea8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 000000c0105c2070 RBX: 00007fabe7211488 RCX: 00007fabe7211488
RDX: 0000000000000007 RSI: 0000000000000004 RDI: ffffffffffffffff
RBP: 000000c000039f28 R08: 00007fabe7125fff R09: 000000c0105ba000
R10: 000000c00001d698 R11: 0000000000000298 R12: 000000c0105c2070
R13: 000000c000000f00 R14: 00000000008db652 R15: 0000000000000000

Allocated by task 31405:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 getname_flags+0xce/0x590 fs/namei.c:140
 do_sys_open+0x26c/0x520 fs/open.c:1079
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 31405:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 putname+0xe1/0x120 fs/namei.c:261
 do_sys_open+0x2ba/0x520 fs/open.c:1094
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880aa6a4880
 which belongs to the cache names_cache of size 4096
The buggy address is located 898 bytes to the right of
 4096-byte region [ffff8880aa6a4880, ffff8880aa6a5880)
The buggy address belongs to the page:
page:ffffea0002a9a900 count:1 mapcount:0 mapping:ffff88823b843380 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002848188 ffffea00018e5008 ffff88823b843380
raw: 0000000000000000 ffff8880aa6a4880 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880aa6a5b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880aa6a5b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880aa6a5c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880aa6a5c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880aa6a5d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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