From: Suraj Jitindar Singh sjitindarsingh@gmail.com
commit 6fbcdd59094ade30db63f32316e9502425d7b256 upstream.
Commit ddf35cf3764b ("powerpc: Use barrier_nospec in copy_from_user()") Added barrier_nospec before loading from user-controlled pointers. The intention was to order the load from the potentially user-controlled pointer vs a previous branch based on an access_ok() check or similar.
In order to achieve the same result, add a barrier_nospec to the raw_copy_in_user() function before loading from such a user-controlled pointer.
Fixes: ddf35cf3764b ("powerpc: Use barrier_nospec in copy_from_user()") Signed-off-by: Suraj Jitindar Singh sjitindarsingh@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/include/asm/uaccess.h | 1 + 1 file changed, 1 insertion(+)
--- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -312,6 +312,7 @@ raw_copy_in_user(void __user *to, const { unsigned long ret;
+ barrier_nospec(); allow_user_access(to, from, n); ret = __copy_tofrom_user(to, from, n); prevent_user_access(to, from, n);