From: Reinette Chatre <reinette.chatre@xxxxxxxxx> [ Upstream commit dda03e2c331b9fc7bbc8fc0de12a6d92d8c18661 ] User provided offset and length is validated when parsing the parameters of the SGX_IOC_ENCLAVE_ADD_PAGES ioctl(). Extract this validation (with consistent use of IS_ALIGNED) into a utility that can be used by the SGX2 ioctl()s that will also provide these values. Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Link: https://lkml.kernel.org/r/767147bc100047abed47fe27c592901adfbb93a2.1652137848.git.reinette.chatre@xxxxxxxxx Stable-dep-of: f0861f49bd94 ("x86/sgx: Add overflow check in sgx_validate_offset_length()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/kernel/cpu/sgx/ioctl.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 83df20e3e633..a66795e0b685 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -372,6 +372,26 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src, return ret; } +/* + * Ensure user provided offset and length values are valid for + * an enclave. + */ +static int sgx_validate_offset_length(struct sgx_encl *encl, + unsigned long offset, + unsigned long length) +{ + if (!IS_ALIGNED(offset, PAGE_SIZE)) + return -EINVAL; + + if (!length || !IS_ALIGNED(length, PAGE_SIZE)) + return -EINVAL; + + if (offset + length - PAGE_SIZE >= encl->size) + return -EINVAL; + + return 0; +} + /** * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES * @encl: an enclave pointer @@ -425,14 +445,10 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg) if (copy_from_user(&add_arg, arg, sizeof(add_arg))) return -EFAULT; - if (!IS_ALIGNED(add_arg.offset, PAGE_SIZE) || - !IS_ALIGNED(add_arg.src, PAGE_SIZE)) - return -EINVAL; - - if (!add_arg.length || add_arg.length & (PAGE_SIZE - 1)) + if (!IS_ALIGNED(add_arg.src, PAGE_SIZE)) return -EINVAL; - if (add_arg.offset + add_arg.length - PAGE_SIZE >= encl->size) + if (sgx_validate_offset_length(encl, add_arg.offset, add_arg.length)) return -EINVAL; if (copy_from_user(&secinfo, (void __user *)add_arg.secinfo, -- 2.35.1
