gwj / at91sam9263 · Commits

Commit d9db889faf1bea70d36e31231bf324ae009c6344

Authored by Jan Kiszka
Committed by Anthony Liguori
1 parent e6da7680

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>
Inline Side-by-side
Showing 1 changed file with 5 additions and 2 deletions
target-i386/kvm.c
  View file @d9db889
@@ -239,8 +239,11 @@ static int kvm_has_msr_star(CPUState *env) @@ -239,8 +239,11 @@ static int kvm_has_msr_star(CPUState *env)
239 if (ret < 0) 239 if (ret < 0)
240 return 0; 240 return 0;
241 241
242 - kvm_msr_list = qemu_mallocz(sizeof(msr_list) +  
243 - msr_list.nmsrs * sizeof(msr_list.indices[0])); 242 + /* Old kernel modules had a bug and could write beyond the provided
  243 + memory. Allocate at least a safe amount of 1K. */
  244 + kvm_msr_list = qemu_mallocz(MAX(1024, sizeof(msr_list) +
  245 + msr_list.nmsrs *
  246 + sizeof(msr_list.indices[0])));
244 247
245 kvm_msr_list->nmsrs = msr_list.nmsrs; 248 kvm_msr_list->nmsrs = msr_list.nmsrs;
246 ret = kvm_ioctl(env->kvm_state, KVM_GET_MSR_INDEX_LIST, kvm_msr_list); 249 ret = kvm_ioctl(env->kvm_state, KVM_GET_MSR_INDEX_LIST, kvm_msr_list);