From: Sean Christopherson Date: Fri, 1 May 2026 20:35:34 +0000 (-0700) Subject: KVM: SEV: Explicitly validate the dst buffer for debug operations X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cb32e895546bf45ebdd0e76ae7a7d783eed2c304;p=thirdparty%2Flinux.git KVM: SEV: Explicitly validate the dst buffer for debug operations When encrypting/decrypting guest memory, explicitly check that the destination is non-NULL and doesn't wrap instead of subtly relying on sev_pin_memory() to perform the check. This will allow adding and using a more focused single-page pinning helper. Link: https://patch.msgid.link/20260501203537.2120074-4-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 00d3bab091d2..9e9b8ca2e9f7 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1357,9 +1357,11 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec) if (copy_from_user(&debug, u64_to_user_ptr(argp->data), sizeof(debug))) return -EFAULT; - if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr) + if (!debug.len || !debug.src_uaddr || !debug.dst_uaddr) return -EINVAL; - if (!debug.dst_uaddr) + + if (debug.src_uaddr + debug.len < debug.src_uaddr || + debug.dst_uaddr + debug.len < debug.dst_uaddr) return -EINVAL; vaddr = debug.src_uaddr;