RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00007fc920eb91d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fffecb1ae6f R14: 00007fc920eb9300 R15: 0000000000022000
==================================================================
BUG: KASAN: slab-out-of-bounds in _decode_session6+0xf56/0x1370 net/ipv6/xfrm6_policy.c:137
Read of size 1 at addr ffff8880a4c54134 by task kworker/1:0/19

CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 __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]
 vti_tunnel_xmit+0x279/0x1850 net/ipv4/ip_vti.c:326
 __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_dad_completed+0x31e/0xb60 net/ipv6/addrconf.c:4152
 addrconf_dad_begin net/ipv6/addrconf.c:3920 [inline]
 addrconf_dad_work+0x7d0/0x10a0 net/ipv6/addrconf.c:4022
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 4692:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 getname_flags+0xce/0x590 fs/namei.c:140
 getname fs/namei.c:211 [inline]
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0x8d/0x2d0 fs/namei.c:3834
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4692:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 putname+0xe1/0x120 fs/namei.c:261
 filename_parentat+0x4da/0x590 fs/namei.c:2399
 filename_create+0x9e/0x490 fs/namei.c:3621
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
 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 ffff8880a4c54a40
 which belongs to the cache names_cache of size 4096
The buggy address is located 2316 bytes to the left of
 4096-byte region [ffff8880a4c54a40, ffff8880a4c55a40)
The buggy address belongs to the page:
page:ffffea0002931500 count:1 mapcount:0 mapping:ffff88823b843380 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea000245a208 ffffea000265e988 ffff88823b843380
raw: 0000000000000000 ffff8880a4c54a40 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a4c54000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a4c54080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a4c54100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                     ^
 ffff8880a4c54180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a4c54200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================