Red Hat Bugzilla – Bug 510087
KVM: limit lapic periodic timer frequency
Last modified: 2014-03-25 20:58:48 EDT
Created attachment 350832 [details]
Description of problem:
Its possible to DoS the host by programming lapic timer
with a very high frequency.
Steps to Reproduce:
1. download kvm-lapic-timer-test.tar.bz2 (attached to this BZ)
2. run ./kvmctl bootstrap time.flat
3. host hangs
Created attachment 350833 [details]
lihuang -> mtosatti
I have ran the reproducer in kvm-83-87.el5.can not reproduce the original issue.
./kvmctl bootstrap time.flat
GUEST: paging enabled
GUEST: apic version: 50014
GUEST: apic existence: PASS
GUEST: self ipi: PASS
waited more than 5 mins. the command is not return.it is OK ?
top - 14:10:56 up 9:46, 3 users, load average: 0.02, 0.34, 0.56
Tasks: 1 total, 0 running, 1 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.1%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 7912832k total, 1982024k used, 5930808k free, 18612k buffers
Swap: 8151032k total, 48k used, 8150984k free, 1816184k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
6172 root 18 0 145m 128m 128m S 0.0 1.7 0:00.18 kvmctl
Yes, this is OK. Without the fix (before kvm-83-87.el5) the host would crash.
ok. Thank you (In reply to comment #9)
> Yes, this is OK. Without the fix (before kvm-83-87.el5) the host would crash.
OK .thank you
setting to *VERIFIED*
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.