Messages in this thread | | | From | Peter Gonda <> | Date | Thu, 14 Nov 2019 13:02:28 -0800 | Subject | Re: [PATCH v3 05/11] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command |
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> + > + /* Check if we are crossing the page boundry */ > + offset = params.guest_uaddr & (PAGE_SIZE - 1); > + if ((params.guest_len + offset > PAGE_SIZE)) > + return -EINVAL;
Just curious spec only says that "System physical of the guest memory region. Must be 16 B aligned with the C-bit set." and "Length of guest memory region. Must be a multiple of 16 B and no more than 16 kB". Why do we want to avoid crossing a page boundary?
Also is there an overflow concern in the conditional because params.guest_len is not checked before this?
> + > + data = kzalloc(sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + hdr = psp_copy_user_blob(params.hdr_uaddr, params.hdr_len); > + if (IS_ERR(hdr)) { > + ret = PTR_ERR(hdr); > + goto e_free; > + } > +
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