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authorJan Kiszka2009-07-02 21:45:47 +0200
committerAvi Kivity2009-08-05 12:58:03 +0200
commite125e7b6944898831b56739a5448e705578bf7e2 (patch)
tree27bdf220e2bedfd20358627563509089e8584003 /arch/x86/kvm/x86.c
parentMerge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus (diff)
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KVM: Fix KVM_GET_MSR_INDEX_LIST
So far, KVM copied the emulated_msrs (only MSR_IA32_MISC_ENABLE) to a wrong address in user space due to broken pointer arithmetic. This caused subtle corruption up there (missing MSR_IA32_MISC_ENABLE had probably no practical relevance). Moreover, the size check for the user-provided kvm_msr_list forgot about emulated MSRs. Cc: stable@kernel.org Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fe5474aec41a..7bc311464fae 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1079,14 +1079,13 @@ long kvm_arch_dev_ioctl(struct file *filp,
if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
goto out;
r = -E2BIG;
- if (n < num_msrs_to_save)
+ if (n < msr_list.nmsrs)
goto out;
r = -EFAULT;
if (copy_to_user(user_msr_list->indices, &msrs_to_save,
num_msrs_to_save * sizeof(u32)))
goto out;
- if (copy_to_user(user_msr_list->indices
- + num_msrs_to_save * sizeof(u32),
+ if (copy_to_user(user_msr_list->indices + num_msrs_to_save,
&emulated_msrs,
ARRAY_SIZE(emulated_msrs) * sizeof(u32)))
goto out;