2022-10-04 23:43:35

by Jarkko Sakkinen

Subject: Re: [PATCH] x86/sgx: Add overflow check in sgx_validate_offset_length()

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 <[email protected]>
> ---
> 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 <[email protected]>

BTW, needs:

Cc: [email protected] # v5.11+

BR, Jarkko

2022-11-08 19:29:42

by Reinette Chatre

Subject: Re: [PATCH] x86/sgx: Add overflow check in sgx_validate_offset_length()

(Move x86 maintainers to "To:")

Hi Maintainers,

Could you please consider this fix for inclusion?

Thank you very much

Reinette

On 10/4/2022 4:15 PM, Jarkko Sakkinen wrote:
> 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 <[email protected]>
>> ---
>> 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 <[email protected]>
>
> BTW, needs:
>
> Cc: [email protected] # v5.11+
>
> BR, Jarkko