6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Radim Krčmář rkrcmar@ventanamicro.com
commit 799766208f09f95677a9ab111b93872d414fbad7 upstream.
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@vger.kernel.org Signed-off-by: Radim Krčmář rkrcmar@ventanamicro.com Reviewed-by: Nutty Liu liujingqi@lanxincomputing.com Reviewed-by: Daniel Henrique Barboza dbarboza@ventanamicro.com Link: https://lore.kernel.org/r/20250805104418.196023-4-rkrcmar@ventanamicro.com Signed-off-by: Anup Patel anup@brainfault.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/kvm/vcpu_vector.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/riscv/kvm/vcpu_vector.c +++ b/arch/riscv/kvm/vcpu_vector.c @@ -181,6 +181,8 @@ int kvm_riscv_vcpu_set_reg_vector(struct 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)