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BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x25d4/0x2e40 fs/ext4/xattr.c:1605
Read of size 4 at addr ffff8881817f0083 by task syz-executor5/13142

CPU: 1 PID: 13142 Comm: syz-executor5 Not tainted 4.14.87+ #21
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 print_address_description+0x60/0x22b mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409
 ext4_xattr_set_entry+0x25d4/0x2e40 fs/ext4/xattr.c:1605
 ext4_xattr_ibody_set+0x73/0x280 fs/ext4/xattr.c:2245
 ext4_xattr_set_handle+0x6a6/0xdc0 fs/ext4/xattr.c:2401
 ext4_initxattrs+0xb8/0x110 fs/ext4/xattr_security.c:43
 security_inode_init_security+0x228/0x310 security/security.c:493
 __ext4_new_inode+0x3473/0x48e0 fs/ext4/ialloc.c:1166
 ext4_mkdir+0x234/0xb40 fs/ext4/namei.c:2625
 vfs_mkdir2+0x3cb/0x640 fs/namei.c:3883
 SYSC_mkdirat fs/namei.c:3912 [inline]
 SyS_mkdirat+0x126/0x220 fs/namei.c:3896
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457679
RSP: 002b:00007f96a8cfec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000380
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f96a8cff6d4
R13: 00000000004bd03f R14: 00000000004d4fa8 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea000605fc00 count:0 mapcount:-127 mapping:          (null) index:0x1
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000001 00000000ffffff80
raw: ffffea0006074420 ffffea0006071420 0000000000000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881817eff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881817f0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881817f0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881817f0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881817f0180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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