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| author | Reinette Chatre <reinette.chatre@intel.com> | 2022-05-10 11:08:46 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-07-07 10:13:02 -0700 |
| commit | dda03e2c331b9fc7bbc8fc0de12a6d92d8c18661 (patch) | |
| tree | ea5e0d06bb8f8aa4327ad85279448153e9aa3c4e /arch/x86/kernel/cpu | |
| parent | c7c6a8a61b0066ba7e891783032dc2a7873c6dc7 (diff) | |
| download | lwn-dda03e2c331b9fc7bbc8fc0de12a6d92d8c18661.tar.gz lwn-dda03e2c331b9fc7bbc8fc0de12a6d92d8c18661.zip | |
x86/sgx: Create utility to validate user provided offset and length
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@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/767147bc100047abed47fe27c592901adfbb93a2.1652137848.git.reinette.chatre@intel.com
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/ioctl.c | 28 |
1 files 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 @@ err_out_free: 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, |