This is a note to let you know that I've just added the patch titled
x86/sgx: Create utility to validate user provided offset and length
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-sgx-create-utility-to-validate-user-provided-off.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3ec706786be50139df3b038f444f2c751a278cc4
Author: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Date: Tue May 10 11:08:46 2022 -0700
x86/sgx: Create utility to validate user provided offset and length
[ 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>
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,
