LBA from '-l xerror' are out of disk sector

[Valerio]

my disk is:
Model Family: Seagate Momentus 5400.6
Device Model: ST9500325AS
Serial Number: 6VE28ZKM
LU WWN Device Id: 5 000c50 018cbece4
Firmware Version: 0002SDM1
User Capacity: 500,107,862,016 bytes [500 GB]
Sector Size: 512 bytes logical/physical
Rotation Rate: 5400 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 2.6, 3.0 Gb/s
Local Time is: Thu Sep 27 01:03:18 2018 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
AAM feature is: Unavailable
APM level is: 254 (maximum performance)
Rd look-ahead is: Enabled
Write cache is: Enabled
ATA Security is: Disabled, NOT FROZEN [SEC1]
Wt Cache Reorder: Unknown

so it has:
$ sudo fdisk -l /dev/sda
Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes

Report from '-l error' say:

---

Error 50 occurred at disk power-on lifetime: 21702 hours (904 days + 6 hours)

When the command that caused the error occurred, the device was active or idle.

After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 51 00 ff ff ff 0f Error: UNC at LBA = 0x0fffffff = 268435455

Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
24 00 01 ff ff ff ef 00 00:40:02.086 READ SECTOR(S) EXT
61 00 08 ff ff ff 4f 00 00:39:58.630 WRITE FPDMA QUEUED
61 00 10 ff ff ff 4f 00 00:39:58.630 WRITE FPDMA QUEUED
61 00 08 ff ff ff 4f 00 00:39:58.629 WRITE FPDMA QUEUED
61 00 08 ff ff ff 4f 00 00:39:58.629 WRITE FPDMA QUEUED

While report from '-l xerror' say:

---

Error 50 [9] occurred at disk power-on lifetime: 21702 hours (904 days + 6 hours)

When the command that caused the error occurred, the device was active or idle.

After command completion occurred, registers were:
ER -- ST COUNT LBA_48 LH LM LL DV DC
-- -- -- == -- == == == -- -- -- -- --
40 -- 51 00 00 00 34 fc 00 a1 04 00 00 Error: UNC at LBA = 0x34fc00a104 = 227566199044

Commands leading to the command that caused the error were:
CR FEATR COUNT LBA_48 LH LM LL DV DC Powered_Up_Time Command/Feature_Name
-- == -- == -- == == == -- -- -- -- -- --------------- --------------------
24 00 00 00 01 00 34 fc 00 a1 04 e0 00 00:40:02.086 READ SECTOR(S) EXT
61 00 00 00 08 00 36 d1 00 77 f8 40 00 00:39:58.630 WRITE FPDMA QUEUED
61 00 00 00 10 00 36 d1 00 77 c8 40 00 00:39:58.630 WRITE FPDMA QUEUED
61 00 00 00 08 00 2f e6 00 af 90 40 00 00:39:58.629 WRITE FPDMA QUEUED
61 00 00 00 08 00 2f e3 00 af d8 40 00 00:39:58.629 WRITE FPDMA QUEUED

The '-l error' seems limited by the 0x0fffffff limitation, but
the '-l xerror' LBA=227566199044 is greather than max disk sector=976773168.

Report from '-l selftest' show the right LBA bad sector:
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Extended offline Self-test routine in progress 40% 21708 -
# 2 Extended offline Completed: read failure 20% 21693 883031044

Also report from '-l xselftest' show the right LBA bad sector:
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Extended offline Self-test routine in progress 40% 21708 -
# 2 Extended offline Completed: read failure 20% 21693 883031044