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BUG: KASAN: use-after-free in memset include/linux/string.h:329 [inline]
BUG: KASAN: use-after-free in __ext4_expand_extra_isize.isra.0+0x10b/0x1c0 fs/ext4/inode.c:5787
Write of size 19862 at addr ffff888193c56fa0 by task syz-executor0/1827

CPU: 1 PID: 1827 Comm: syz-executor0 Not tainted 4.14.97+ #4
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 print_address_description+0x60/0x226 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x88/0x2a5 mm/kasan/report.c:393

The buggy address belongs to the page:
page:ffffea00064f1580 count:2 mapcount:0 mapping:ffff8881d5ab0950 index:0x440
flags: 0x4000000000001074(referenced|dirty|lru|active|private)
raw: 4000000000001074 ffff8881d5ab0950 0000000000000440 00000002ffffffff
raw: ffffea0006b17c60 ffffea00065173a0 ffff888194d3e7e0 ffff8881d641aa80
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8881d641aa80

Memory state around the buggy address:
 ffff888193c57f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888193c57f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888193c58000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888193c58080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888193c58100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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