Merge tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block

[linux.git] / lib / usercopy.c

diff --git a/lib/usercopy.c b/lib/usercopy.c
index b26509f112f95e49fe3a2c2cb875467843b1e518..7413dd300516e5405d92858a033b36c0eeb0399c 100644 (file)
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/bitops.h>
+#include <linux/fault-inject-usercopy.h>
 #include <linux/instrumented.h>
 #include <linux/uaccess.h>
 
@@ -10,7 +11,7 @@ unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n
 {
        unsigned long res = n;
        might_fault();
-       if (likely(access_ok(from, n))) {
+       if (!should_fail_usercopy() && likely(access_ok(from, n))) {
                instrument_copy_from_user(to, from, n);
                res = raw_copy_from_user(to, from, n);
        }
@@ -25,6 +26,8 @@ EXPORT_SYMBOL(_copy_from_user);
 unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n)
 {
        might_fault();
+       if (should_fail_usercopy())
+               return n;
        if (likely(access_ok(to, n))) {
                instrument_copy_to_user(to, from, n);
                n = raw_copy_to_user(to, from, n);