mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-04 16:15:11 +00:00
KVM: SVM: Fix potential overflow in SEV's send|receive_update_data()
commitf94f053aa3
upstream. KVM_SEV_SEND_UPDATE_DATA and KVM_SEV_RECEIVE_UPDATE_DATA have an integer overflow issue. Params.guest_len and offset are both 32 bits wide, with a large params.guest_len the check to confirm a page boundary is not crossed can falsely pass: /* Check if we are crossing the page boundary * offset = params.guest_uaddr & (PAGE_SIZE - 1); if ((params.guest_len + offset > PAGE_SIZE)) Add an additional check to confirm that params.guest_len itself is not greater than PAGE_SIZE. Note, this isn't a security concern as overflow can happen if and only if params.guest_len is greater than 0xfffff000, and the FW spec says these commands fail with lengths greater than 16KB, i.e. the PSP will detect KVM's goof. Fixes:15fb7de1a7
("KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command") Fixes:d3d1af85e2
("KVM: SVM: Add KVM_SEND_UPDATE_DATA command") Reported-by: Andy Nguyen <theflow@google.com> Suggested-by: Thomas Lendacky <thomas.lendacky@amd.com> Signed-off-by: Peter Gonda <pgonda@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20230207171354.4012821-1-pgonda@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
11d4b35674
commit
033a4c0621
1 changed files with 2 additions and 2 deletions
|
@ -1277,7 +1277,7 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
|
|||
|
||||
/* Check if we are crossing the page boundary */
|
||||
offset = params.guest_uaddr & (PAGE_SIZE - 1);
|
||||
if ((params.guest_len + offset > PAGE_SIZE))
|
||||
if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
|
||||
return -EINVAL;
|
||||
|
||||
/* Pin guest memory */
|
||||
|
@ -1457,7 +1457,7 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
|
|||
|
||||
/* Check if we are crossing the page boundary */
|
||||
offset = params.guest_uaddr & (PAGE_SIZE - 1);
|
||||
if ((params.guest_len + offset > PAGE_SIZE))
|
||||
if (params.guest_len > PAGE_SIZE || (params.guest_len + offset) > PAGE_SIZE)
|
||||
return -EINVAL;
|
||||
|
||||
hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len);
|
||||
|
|
Loading…
Reference in a new issue