kvm: Work around borken MSR_GET_INDEX_LIST

Allocate enough memory for KVM_GET_MSR_INDEX_LIST as older kernels shot
far beyond their limits, corrupting user space memory.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jan Kiszka 2009-07-02 22:04:48 +02:00 committed by Anthony Liguori
parent e6da768000
commit d9db889faf

View File

@ -239,8 +239,11 @@ static int kvm_has_msr_star(CPUState *env)
if (ret < 0)
return 0;
kvm_msr_list = qemu_mallocz(sizeof(msr_list) +
msr_list.nmsrs * sizeof(msr_list.indices[0]));
/* Old kernel modules had a bug and could write beyond the provided
memory. Allocate at least a safe amount of 1K. */
kvm_msr_list = qemu_mallocz(MAX(1024, sizeof(msr_list) +
msr_list.nmsrs *
sizeof(msr_list.indices[0])));
kvm_msr_list->nmsrs = msr_list.nmsrs;
ret = kvm_ioctl(env->kvm_state, KVM_GET_MSR_INDEX_LIST, kvm_msr_list);