Re: hunting memory corruption bug in 6.18.x

[Nikola Ciprich]

> 
> Sure! And I have more good news: after applying 55780d8a1dcc
> to 6.18.56, I was able to perform more than 30 migrations without
> a glitch. After booting back into 6.18.56 without it, both VMs
> crashed within 2-3 migrations. Furthermore, some memory apparently
> got corrupted on one of the hosts, since various commands started
> crashing too:
> 
> [  303.466091] traps: systemd-logind[3085] trap invalid opcode ip:7f7b5667e616 sp:7ffe1afdec38 error:0 in libsystemd-shared-252.so[7e616,7f7b5666d000+22e000]
> [  303.493810] traps: systemd-coredum[11269] trap invalid opcode ip:7fc6bf67f614 sp:7ffc075da958 error:0 in libsystemd-shared-252.so[7f614,7fc6bf66d000+22e000]
> [  377.528955] traps: systemd[5607] trap invalid opcode ip:7f791447e616 sp:7ffe83e61cf8 error:0 in libsystemd-shared-252.so[7e616,7f791446d000+22e000]
> [  377.556993] traps: systemd-coredum[12080] trap invalid opcode ip:7f97ce07f614 sp:7ffe28b56a88 error:0 in libsystemd-shared-252.so[7f614,7f97ce06d000+22e000]
> [ 3746.173043] traps: hostnamectl[45846] trap invalid opcode ip:7fe00cc7f614 sp:7fff89916e48 error:0 in libsystemd-shared-252.so[7f614,7fe00cc6d000+22e000]
> [ 3746.202305] traps: systemd-coredum[45847] trap invalid opcode ip:7f7fe9e7f614 sp:7ffea227cfa8 error:0 in libsystemd-shared-252.so[7f614,7f7fe9e6d000+22e000]
> [ 3750.581940] traps: systemctl[45903] trap invalid opcode ip:7fbb8967f614 sp:7fff733e5748 error:0 in libsystemd-shared-252.so[7f614,7fbb8966d000+22e000]
> [ 3750.612651] traps: systemd-coredum[45904] trap invalid opcode ip:7f90d347f614 sp:7ffdc7f55148 error:0 in libsystemd-shared-252.so[7f614,7f90d346d000+22e000]
> 
> I'm not sure if this is of any use, but I collected a vmcore of
> this state by intentionally crashing the host via /proc/sysrq-trigger.
> 
> Anyway, I'll give 55780d8a1dcc some more migration rounds, but it looks
> promising.

500+ migrations back and forth, no issues. I consider this solved and am rolling
out the patched kernel; I’ll report if anything new turns up.

Definitely a -stable candidate. Andrew, will you send it to Greg, or shall I?

Thank you all for spending time on this!

BR

nik

> 
> I'll report soon
> 
> Cheers, nik
> 

-- 
Ing. Nikola CIPRICH
technický ředitel

+420 591 166 214
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nikola.ciprich@xxxxxxxxxxx

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