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BUG: KASAN: use-after-free in _copy_to_user+0xe9/0x110 lib/usercopy.c:27
Read of size 979 at addr ffff88018efffffc by task syz-executor2/18273

CPU: 0 PID: 18273 Comm: syz-executor2 Not tainted 4.18.0-rc3+ #58
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+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 _copy_to_user+0xe9/0x110 lib/usercopy.c:27
 copy_to_user include/linux/uaccess.h:155 [inline]
 bpf_test_finish.isra.7+0xee/0x1f0 net/bpf/test_run.c:59
 bpf_prog_test_run_skb+0x7d7/0xa30 net/bpf/test_run.c:144
 bpf_prog_test_run+0x130/0x1a0 kernel/bpf/syscall.c:1686
 __do_sys_bpf kernel/bpf/syscall.c:2323 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:2267 [inline]
 __x64_sys_bpf+0x3d8/0x510 kernel/bpf/syscall.c:2267
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fbc73924c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fbc739256d4 RCX: 0000000000455ab9
RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004bb71f R14: 00000000004c8b00 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00063bffc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 ffffea00063bffc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88018efffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88018effff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88018effff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88018f000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88018f000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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