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BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x169f/0x1810 arch/x86/kernel/unwind_orc.c:470
Read of size 8 at addr ffff8881a761f1d8 by task syz-executor.3/13002

CPU: 0 PID: 13002 Comm: syz-executor.3 Not tainted 4.14.156-syzkaller #0
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xe5/0x154 lib/dump_stack.c:58
 print_address_description+0x60/0x226 mm/kasan/report.c:187
 __kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316
 unwind_next_frame+0x169f/0x1810 arch/x86/kernel/unwind_orc.c:470
 perf_callchain_kernel+0x3a0/0x540 arch/x86/events/core.c:2338
 get_perf_callchain+0x2f5/0x770 kernel/events/callchain.c:217
 perf_callchain+0x147/0x190 kernel/events/callchain.c:190
 perf_prepare_sample+0x6a8/0x1360 kernel/events/core.c:6149
 __perf_event_output kernel/events/core.c:6265 [inline]
 perf_event_output_forward+0xdc/0x220 kernel/events/core.c:6283
 __perf_event_overflow+0x12d/0x340 kernel/events/core.c:7541
 perf_swevent_overflow+0x7a/0xf0 kernel/events/core.c:7617
 perf_swevent_event+0x19c/0x270 kernel/events/core.c:7650
 perf_tp_event+0x633/0x7f0 kernel/events/core.c:8079
 perf_trace_run_bpf_submit kernel/events/core.c:8049 [inline]
 perf_trace_run_bpf_submit+0x113/0x170 kernel/events/core.c:8035
 perf_trace_lock_acquire+0x341/0x4e0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x279/0x360 kernel/locking/lockdep.c:3993
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152
 spin_lock include/linux/spinlock.h:317 [inline]
 dd_bio_merge+0xde/0x170 block/mq-deadline.c:378
 __blk_mq_sched_bio_merge+0x41e/0x770 block/blk-mq-sched.c:236
 blk_mq_sched_bio_merge block/blk-mq-sched.h:44 [inline]
 blk_mq_make_request+0x1ee/0x19c0 block/blk-mq.c:1662
 generic_make_request block/blk-core.c:2228 [inline]
 generic_make_request+0x212/0x880 block/blk-core.c:2172
 submit_bio+0xa7/0x390 block/blk-core.c:2317
 ext4_io_submit+0x16a/0x200 fs/ext4/page-io.c:348
 ext4_writepages+0x1308/0x30a0 fs/ext4/inode.c:2933
 do_writepages+0xe5/0x280 mm/page-writeback.c:2348
 __filemap_fdatawrite_range+0x206/0x2a0 mm/filemap.c:348
ip6_tunnel: ‘ xmit: Local address not yet configured!
 filemap_write_and_wait_range mm/filemap.c:581 [inline]
 filemap_write_and_wait_range+0x59/0xd0 mm/filemap.c:575
ip6_tunnel: { xmit: Local address not yet configured!
 generic_file_direct_write+0x324/0x430 mm/filemap.c:3012
 __generic_file_write_iter+0x209/0x550 mm/filemap.c:3215
 ext4_file_write_iter+0x58f/0xdb0 fs/ext4/file.c:268
 call_write_iter include/linux/fs.h:1798 [inline]
 new_sync_write fs/read_write.c:471 [inline]
 __vfs_write+0x401/0x5a0 fs/read_write.c:484
 vfs_write+0x17f/0x4d0 fs/read_write.c:546
 SYSC_write fs/read_write.c:594 [inline]
 SyS_write+0x102/0x250 fs/read_write.c:586
 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a649
RSP: 002b:00007f3ae72f1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a649
RDX: 00000000175d900f RSI: 0000000020000200 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3ae72f26d4
R13: 00000000004cb193 R14: 00000000004e38f0 R15: 00000000ffffffff

ip6_tunnel: | xmit: Local address not yet configured!
The buggy address belongs to the page:
page:ffffea00069d87c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 dead000000000200 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881a761f080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881a761f100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881a761f180: 00 00 f1 f1 f1 f1 f1 f1 04 f2 00 f3 f3 f3 00 00
                                                    ^
ip6_tunnel: â xmit: Local address not yet configured!
 ffff8881a761f200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881a761f280: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3
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