From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Date: Mon, 15 Jun 2020 17:41:12 -0500
Subject: [PATCH] cifs: misc: Use array_size() in if-statement controlling
 expression
Git-commit: bf1028a41eaf0ce39518cbdda34cdb717f16364a
Patch-mainline: v5.8-rc3
References: bsc#1192606

Use array_size() instead of the open-coded version in the controlling
expression of the if statement.

Also, while there, use the preferred form for passing a size of a struct.
The alternative form where struct name is spelled out hurts readability
and introduces an opportunity for a bug when the pointer variable type is
changed but the corresponding sizeof that is passed as argument is not.

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 fs/cifs/misc.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 56791a692c8b..e44d049142d0 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -844,28 +844,26 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 	struct bio_vec *bv = NULL;
 
 	if (iov_iter_is_kvec(iter)) {
-		memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
+		memcpy(&ctx->iter, iter, sizeof(*iter));
 		ctx->len = count;
 		iov_iter_advance(iter, count);
 		return 0;
 	}
 
-	if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
-		bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
-				   GFP_KERNEL);
+	if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
+		bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
 
 	if (!bv) {
-		bv = vmalloc(array_size(max_pages, sizeof(struct bio_vec)));
+		bv = vmalloc(array_size(max_pages, sizeof(*bv)));
 		if (!bv)
 			return -ENOMEM;
 	}
 
-	if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
-		pages = kmalloc_array(max_pages, sizeof(struct page *),
-				      GFP_KERNEL);
+	if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
+		pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
 
 	if (!pages) {
-		pages = vmalloc(array_size(max_pages, sizeof(struct page *)));
+		pages = vmalloc(array_size(max_pages, sizeof(*pages)));
 		if (!pages) {
 			kvfree(bv);
 			return -ENOMEM;
-- 
2.33.1