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-rw-r--r--lib/usercopy.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/usercopy.c b/lib/usercopy.c
index 3744b2a8e..1e99c1baf 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/uaccess.h>
+#include <linux/nospec.h>
/* out-of-line parts */
@@ -9,6 +10,12 @@ unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n
unsigned long res = n;
might_fault();
if (likely(access_ok(VERIFY_READ, from, n))) {
+ /*
+ * Ensure that bad access_ok() speculation will not
+ * lead to nasty side effects *after* the copy is
+ * finished:
+ */
+ barrier_nospec();
kasan_check_write(to, n);
res = raw_copy_from_user(to, from, n);
}