Add basic success/failure checking of copy_in_user() which copies data from userspace to userspace (or kernel to kernel), and its unchecking cousin __copy_in_user() which assumes that access_ok() has already been used as appropriate. The following cases are checked: - __copy_in_user/copy_in_user from user to user should succeed. - __copy_in_user/copy_in_user involving 1 or 2 kernel pointers should not succeed. - __copy_in_user/copy_in_user from kernel to kernel should succeed when user address limit is set for kernel accesses. New tests: - legitimate copy_in_user - legitimate __copy_in_user - illegal all-kernel copy_in_user - illegal copy_in_user to kernel - illegal copy_in_user from kernel - illegal all-kernel __copy_in_user - illegal __copy_in_user to kernel - illegal __copy_in_user from kernel - legitimate all-kernel copy_in_user - legitimate all-kernel __copy_in_user Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/test_user_copy.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c index 4ec2cfa916c1..310e796beef6 100644 --- a/lib/test_user_copy.c +++ b/lib/test_user_copy.c @@ -64,6 +64,8 @@ static int __init test_user_copy_init(void) "legitimate copy_from_user failed"); ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE), "legitimate copy_to_user failed"); + ret |= test(copy_in_user(usermem, usermem + PAGE_SIZE, PAGE_SIZE), + "legitimate copy_in_user failed"); ret |= test(get_user(value, (unsigned long __user *)usermem), "legitimate get_user failed"); ret |= test(put_user(value, (unsigned long __user *)usermem), @@ -79,6 +81,8 @@ static int __init test_user_copy_init(void) "legitimate __copy_from_user failed"); ret |= test(__copy_to_user(usermem, kmem, PAGE_SIZE), "legitimate __copy_to_user failed"); + ret |= test(__copy_in_user(usermem, usermem + PAGE_SIZE, PAGE_SIZE), + "legitimate __copy_in_user failed"); ret |= test(__get_user(value, (unsigned long __user *)usermem), "legitimate __get_user failed"); ret |= test(__put_user(value, (unsigned long __user *)usermem), @@ -99,6 +103,15 @@ static int __init test_user_copy_init(void) ret |= test(!copy_to_user((char __user *)kmem, bad_usermem, PAGE_SIZE), "illegal reversed copy_to_user passed"); + ret |= test(!copy_in_user((char __user *)kmem, + (char __user *)(kmem + PAGE_SIZE), PAGE_SIZE), + "illegal all-kernel copy_in_user passed"); + ret |= test(!copy_in_user((char __user *)kmem, usermem, + PAGE_SIZE), + "illegal copy_in_user to kernel passed"); + ret |= test(!copy_in_user(usermem, (char __user *)kmem, + PAGE_SIZE), + "illegal copy_in_user from kernel passed"); ret |= test(!get_user(value, (unsigned long __user *)kmem), "illegal get_user passed"); ret |= test(!put_user(value, (unsigned long __user *)kmem), @@ -130,6 +143,16 @@ static int __init test_user_copy_init(void) ret |= test(!__copy_to_user((char __user *)kmem, bad_usermem, PAGE_SIZE), "illegal reversed __copy_to_user passed"); + ret |= test(!__copy_in_user((char __user *)kmem, + (char __user *)(kmem + PAGE_SIZE), + PAGE_SIZE), + "illegal all-kernel __copy_in_user passed"); + ret |= test(!__copy_in_user((char __user *)kmem, usermem, + PAGE_SIZE), + "illegal __copy_in_user to kernel passed"); + ret |= test(!__copy_in_user(usermem, (char __user *)kmem, + PAGE_SIZE), + "illegal __copy_in_user from kernel passed"); ret |= test(!__get_user(value, (unsigned long __user *)kmem), "illegal __get_user passed"); ret |= test(!__put_user(value, (unsigned long __user *)kmem), @@ -152,6 +175,9 @@ static int __init test_user_copy_init(void) ret |= test(copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, PAGE_SIZE), "legitimate all-kernel copy_to_user failed"); + ret |= test(copy_in_user((char __user *)kmem, + (char __user *)(kmem + PAGE_SIZE), PAGE_SIZE), + "legitimate all-kernel copy_in_user failed"); ret |= test(get_user(value, (unsigned long __user *)kmem), "legitimate kernel get_user failed"); ret |= test(put_user(value, (unsigned long __user *)kmem), @@ -170,6 +196,10 @@ static int __init test_user_copy_init(void) ret |= test(__copy_to_user((char __user *)kmem, kmem + PAGE_SIZE, PAGE_SIZE), "legitimate all-kernel __copy_to_user failed"); + ret |= test(__copy_in_user((char __user *)kmem, + (char __user *)(kmem + PAGE_SIZE), + PAGE_SIZE), + "legitimate all-kernel __copy_in_user failed"); ret |= test(__get_user(value, (unsigned long __user *)kmem), "legitimate kernel __get_user failed"); ret |= test(__put_user(value, (unsigned long __user *)kmem), -- 2.3.6
