IPMI: after SEL overflow, `ipmitool sel list` collapsed to a single row

[louis-nexthop]

We noticed that when IPMI SEL ring buffer is full, adding a new entry (via the x86 host) will mess up the list command

Here is an example:

# Initial: have 129 SEL records
[root@fboss ~]# ipmitool sel list | wc -l
129

# Bug: ID "1" is duplicated
[root@fboss ~]# ipmitool sel list | head -4
   1 | 05/14/2026 | 20:40:26 | Processor #0x40 | Uncorrectable machine check exception | Asserted
   1 | 05/14/2026 | 20:40:26 | Processor #0x40 | Uncorrectable machine check exception | Asserted
   2 | 05/14/2026 | 20:42:44 | Processor #0x40 | Uncorrectable machine check exception | Asserted
   3 | 05/14/2026 | 20:45:02 | Processor #0x40 | Uncorrectable machine check exception | Asserted
[root@fboss ~]# ipmitool sel list | tail -3
  7e | 05/28/2026 | 05:01:09 | Temperature #0x17 |  | Asserted
  7f | 05/28/2026 | 05:03:36 | Temperature #0x17 |  | Asserted
  80 | 05/28/2026 | 05:03:50 | Temperature #0x17 |  | Asserted

# Then: add 1 more record
[root@fboss ~]# ipmitool raw 0x0a 0x44 0x01 0x00 0x02 0xab 0xcd 0xef 0x00 0x01 0x00 0x04 0x01 0x17 0x00 0xa0 0x04 0x07
 00 00

# Bug: new entry is not shown. It only output the record with ID "2" which was existing
[root@fboss ~]# ipmitool sel list | wc -l
1
[root@fboss ~]# ipmitool sel list
   2 | 05/14/2026 | 20:42:44 | Processor #0x40 | Uncorrectable machine check exception | Asserted