Commit e73af4fd authored by Al Viro's avatar Al Viro Committed by Sasha Levin

asm-generic: make get_user() clear the destination on errors

[ Upstream commit 9ad18b75 ]

both for access_ok() failures and for faults halfway through

Cc: stable@vger.kernel.org
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
parent a4b77785
......@@ -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)
......
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