uaccess: Fix is_source param for check_copy_size() in copy_to_iter_mcsafe()

davejiang · djbw · commit dfb06cba8c73 · 2018-09-12T14:58:47.000-07:00
copy_to_iter_mcsafe() is passing in the is_source parameter as "false" to check_copy_size(). This is different than what copy_to_iter() does. Also, the addr parameter passed to check_copy_size() is the source so therefore we should be passing in "true" instead. Fixes: 8780356 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()") Cc: <stable@vger.kernel.org> Reported-by: Fan Du <fan.du@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reported-by: Wenwei Tao <wenwei.tww@alibaba-inc.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/uio.h b/include/linux/uio.h
@@ -172,7 +172,7 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 static __always_inline __must_check
 size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
 {
-	if (unlikely(!check_copy_size(addr, bytes, false)))
+	if (unlikely(!check_copy_size(addr, bytes, true)))
 		return 0;
 	else
 		return _copy_to_iter_mcsafe(addr, bytes, i);

Original file line number	Diff line number	Diff line change
`@@ -172,7 +172,7 @@ size_t copy_from_iter_flushcache(void addr, size_t bytes, struct iov_iter i)`
`172`	`172`	`static __always_inline __must_check`
`173`	`173`	`size_t copy_to_iter_mcsafe(void addr, size_t bytes, struct iov_iter i)`
`174`	`174`	`{`
`175`		`- if (unlikely(!check_copy_size(addr, bytes, false)))`
	`175`	`+ if (unlikely(!check_copy_size(addr, bytes, true)))`
`176`	`176`	`return 0;`
`177`	`177`	`else`
`178`	`178`	`return _copy_to_iter_mcsafe(addr, bytes, i);`