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BUG: KASAN: out-of-bounds in _copy_to_user+0xe9/0x110 lib/usercopy.c:27
Read of size 978 at addr ffff8801907ffff2 by task syz-executor2/17209

CPU: 1 PID: 17209 Comm: syz-executor2 Not tainted 4.18.0-rc3+ #48
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: 0033:0x455e29
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:00007f8f5b3f3c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f8f5b3f46d4 RCX: 0000000000455e29
RDX: 0000000000000028 RSI: 0000000020000280 RDI: 000000000000000a
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004bbaee R14: 00000000004c8d20 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006418000 count:1 mapcount:1 mapping:ffff8801c20dad99 index:0x20000 compound_mapcount: 1
flags: 0x2fffc0000048068(uptodate|lru|active|head|swapbacked)
raw: 02fffc0000048068 ffffea0006a63a88 ffffea00071a6408 ffff8801c20dad99
raw: 0000000000020000 0000000000000000 00000001ffffffff ffff8801cfe22600
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801cfe22600

Memory state around the buggy address:
 ffff880190800280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880190800300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880190800380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                              ^
 ffff880190800400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880190800480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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