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BUG: KASAN: use-after-free in memmove include/linux/string.h:374 [inline]
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0xbef/0x3770 fs/ext4/xattr.c:1734
Read of size 4 at addr ffff888081f75ffe by task syz-fuzzer/10373

CPU: 0 PID: 10373 Comm: syz-fuzzer Not tainted 5.3.0-rc3+ #96
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:612
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memmove+0x24/0x50 mm/kasan/common.c:113
 memmove include/linux/string.h:374 [inline]
 ext4_xattr_set_entry+0xbef/0x3770 fs/ext4/xattr.c:1734
 ext4_xattr_ibody_set+0x80/0x2d0 fs/ext4/xattr.c:2236
 ext4_xattr_set_handle+0x821/0x1090 fs/ext4/xattr.c:2392
 ext4_initxattrs+0xc0/0x130 fs/ext4/xattr_security.c:43
 security_inode_init_security security/security.c:956 [inline]
 security_inode_init_security+0x2c8/0x3b0 security/security.c:929
 ext4_init_security+0x34/0x40 fs/ext4/xattr_security.c:57
 __ext4_new_inode+0x3b88/0x4e50 fs/ext4/ialloc.c:1160
 ext4_mkdir+0x3df/0xe20 fs/ext4/namei.c:2763
 vfs_mkdir+0x42e/0x670 fs/namei.c:3815
 do_mkdirat+0x234/0x2a0 fs/namei.c:3838
 __do_sys_mkdirat fs/namei.c:3849 [inline]
 __se_sys_mkdirat fs/namei.c:3847 [inline]
 __x64_sys_mkdirat+0x76/0xb0 fs/namei.c:3847
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x47fcb4
Code: ff ff cc cc cc cc e8 2b 41 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 45 31 d2 45 31 c0 45 31 c9 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c433718f40 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047fcb4
RDX: 00000000000001c0 RSI: 000000c420687320 RDI: ffffffffffffff9c
RBP: 000000c433718fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001000000
R13: 0000000001000000 R14: 00007f6aed7af000 R15: 0000000000000080

The buggy address belongs to the page:
page:ffffea000207dd40 refcount:2 mapcount:0 mapping:ffff8880a2d6bb18 index:0x42b
def_blk_aops 
flags: 0x1fffc000000203a(referenced|dirty|lru|active|private)
raw: 01fffc000000203a ffffea0001e90088 ffffea00020d9b08 ffff8880a2d6bb18
raw: 000000000000042b ffff888090b399d8 00000002ffffffff ffff88805ec3cec0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88805ec3cec0

Memory state around the buggy address:
 ffff888081f75f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888081f75f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888081f76000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888081f76080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888081f76100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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