summary refs log tree commit diff
path: root/include/asm-generic
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2016-08-17 23:19:01 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2016-09-13 17:49:10 -0400
commit9ad18b75c2f6e4a78ce204e79f37781f8815c0fa (patch)
treec9bff1bf167317cf688f9919b4bc45c560a3326c /include/asm-generic
parent2545e5da080b4839dd859e3b09343a884f6ab0e3 (diff)
downloadlinux-9ad18b75c2f6e4a78ce204e79f37781f8815c0fa.tar.gz
asm-generic: make get_user() clear the destination on errors
both for access_ok() failures and for faults halfway through

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/uaccess.h10
1 files changed, 7 insertions, 3 deletions
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 04e21a41796a..32901d11f8c4 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -230,14 +230,18 @@ extern int __put_user_bad(void) __attribute__((noreturn));
 	might_fault();						\
 	access_ok(VERIFY_READ, __p, sizeof(*ptr)) ?		\
 		__get_user((x), (__typeof__(*(ptr)) *)__p) :	\
-		-EFAULT;					\
+		((x) = (__typeof__(*(ptr)))0,-EFAULT);		\
 })
 
 #ifndef __get_user_fn
 static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
 {
-	size = __copy_from_user(x, ptr, size);
-	return size ? -EFAULT : size;
+	size_t n = __copy_from_user(x, ptr, size);
+	if (unlikely(n)) {
+		memset(x + (size - n), 0, n);
+		return -EFAULT;
+	}
+	return 0;
 }
 
 #define __get_user_fn(sz, u, k)	__get_user_fn(sz, u, k)