From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 3 Mar 2021 10:59:12 +0000 (+0300)
Subject: rsxx: Return -EFAULT if copy_to_user() fails
X-Git-Tag: v4.4.261~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12a9ffac8d54c04792b81203f26e4b02c060bad5;p=thirdparty%2Fkernel%2Fstable.git

rsxx: Return -EFAULT if copy_to_user() fails

[ Upstream commit 77516d25f54912a7baedeeac1b1b828b6f285152 ]

The copy_to_user() function returns the number of bytes remaining but
we want to return -EFAULT to the user if it can't complete the copy.
The "st" variable only holds zero on success or negative error codes on
failure so the type should be int.

Fixes: 36f988e978f8 ("rsxx: Adding in debugfs entries.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/block/rsxx/core.c b/drivers/block/rsxx/core.c
index 620a3a67cdd52..0d9137408e3c8 100644
--- a/drivers/block/rsxx/core.c
+++ b/drivers/block/rsxx/core.c
@@ -180,15 +180,17 @@ static ssize_t rsxx_cram_read(struct file *fp, char __user *ubuf,
 {
 	struct rsxx_cardinfo *card = file_inode(fp)->i_private;
 	char *buf;
-	ssize_t st;
+	int st;
 
 	buf = kzalloc(cnt, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
 	st = rsxx_creg_read(card, CREG_ADD_CRAM + (u32)*ppos, cnt, buf, 1);
-	if (!st)
-		st = copy_to_user(ubuf, buf, cnt);
+	if (!st) {
+		if (copy_to_user(ubuf, buf, cnt))
+			st = -EFAULT;
+	}
 	kfree(buf);
 	if (st)
 		return st;