[PATCH 4.4 091/118] microblaze: fix copy_from_user()
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-09-22 19:00:20
Also in:
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4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro <viro@zeniv.linux.org.uk> commit d0cf385160c12abd109746cad1f13e3b3e8b50b8 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/microblaze/include/asm/uaccess.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h@@ -373,10 +373,13 @@ extern long __user_bad(void); static inline long copy_from_user(void *to, const void __user *from, unsigned long n) { + unsigned long res = n; might_fault(); - if (access_ok(VERIFY_READ, from, n)) - return __copy_from_user(to, from, n); - return n; + if (likely(access_ok(VERIFY_READ, from, n))) + res = __copy_from_user(to, from, n); + if (unlikely(res)) + memset(to + (n - res), 0, res); + return res; } #define __copy_to_user(to, from, n) \