On Wed, Oct 05, 2022 at 12:59:03AM +0200, Borys wrote:
> sgx_validate_offset_length() function verifies "offset" and "length"
> arguments provided by userspace, but was missing an overflow check on
> their addition.
> This code was originally introduced in commit c6d26d370767 ("x86/sgx:
> Add SGX_IOC_ENCLAVE_ADD_PAGES") and later refactored in commit
> dda03e2c331b ("x86/sgx: Create utility to validate user provided offset
> and length").
>
> Fixes: c6d26d370767 ("x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES")
> Signed-off-by: Borys Popławski <borysp@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> Applies on top of tip/x86/sgx ee56a283988d739c25d2d00ffb22707cb487ab47
>
> arch/x86/kernel/cpu/sgx/ioctl.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
> index ebe79d60619f..da8b8ea6b063 100644
> --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> @@ -356,6 +356,9 @@ static int sgx_validate_offset_length(struct sgx_encl *encl,
> if (!length || !IS_ALIGNED(length, PAGE_SIZE))
> return -EINVAL;
>
> + if (offset + length < offset)
> + return -EINVAL;
> +
> if (offset + length - PAGE_SIZE >= encl->size)
> return -EINVAL;
>
> --
> 2.37.3
>
Thank you.
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
BTW, needs:
Cc: stable@xxxxxxxxxxxxxxx # v5.11+
BR, Jarkko
