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authorDavid Rientjes <rientjes@google.com>2019-03-25 11:47:31 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2019-04-05 20:49:42 +0200
commitb86bc2858b389255cd44555ce4b1e427b2b770c0 (patch)
tree0744c853c7f9e063f9349963b306eb0bef0d72a4 /arch
parentede885ecb2cdf8a8dd5367702e3d964ec846a2d5 (diff)
downloadlinux-stericsson-b86bc2858b389255cd44555ce4b1e427b2b770c0.tar.gz
KVM: SVM: prevent DBG_DECRYPT and DBG_ENCRYPT overflow
This ensures that the address and length provided to DBG_DECRYPT and DBG_ENCRYPT do not cause an overflow. At the same time, pass the actual number of pages pinned in memory to sev_unpin_memory() as a cleanup. Reported-by: Cfir Cohen <cfir@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 947c35a1e545..e0a791c3d4fc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6799,7 +6799,8 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
struct page **src_p, **dst_p;
struct kvm_sev_dbg debug;
unsigned long n;
- int ret, size;
+ unsigned int size;
+ int ret;
if (!sev_guest(kvm))
return -ENOTTY;
@@ -6807,6 +6808,11 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
if (copy_from_user(&debug, (void __user *)(uintptr_t)argp->data, sizeof(debug)))
return -EFAULT;
+ if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
+ return -EINVAL;
+ if (!debug.dst_uaddr)
+ return -EINVAL;
+
vaddr = debug.src_uaddr;
size = debug.len;
vaddr_end = vaddr + size;
@@ -6857,8 +6863,8 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
dst_vaddr,
len, &argp->error);
- sev_unpin_memory(kvm, src_p, 1);
- sev_unpin_memory(kvm, dst_p, 1);
+ sev_unpin_memory(kvm, src_p, n);
+ sev_unpin_memory(kvm, dst_p, n);
if (ret)
goto err;