On 8/5/25 7:44 AM, Radim Krčmář wrote:
The userspace load can put up to 2048 bits into an xlen bit stack
buffer. We want only xlen bits, so check the size beforehand.
Fixes: 2fa290372dfe ("RISC-V: KVM: add 'vlenb' Vector CSR")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxxxxxxxx>
---
Reviewed-by: Daniel Henrique Barboza <dbarboza@xxxxxxxxxxxxxxxx>
arch/riscv/kvm/vcpu_vector.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c
index a5f88cb717f3..05f3cc2d8e31 100644
--- a/arch/riscv/kvm/vcpu_vector.c
+++ b/arch/riscv/kvm/vcpu_vector.c
@@ -182,6 +182,8 @@ int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu,
struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
unsigned long reg_val;
+ if (reg_size != sizeof(reg_val))
+ return -EINVAL;
if (copy_from_user(®_val, uaddr, reg_size))
return -EFAULT;
if (reg_val != cntx->vector.vlenb)
