[PATCH] uio: fix is_source param for check_copy_size() in copy_to_iter_mcsafe()

From: Dave Jiang
Date: Wed Sep 05 2018 - 16:31:45 EST


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: 8780356ef630 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()")

Reported-by: Fan Du <fan.du@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
---
include/linux/uio.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 409c845d4cd3..422b1c01ee0d 100644
--- 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);