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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
parent2545e5da080b4839dd859e3b09343a884f6ab0e3 (diff)
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>
-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)