From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 15 Jul 2022 10:35:18 +0000 (+0300)
Subject: wifi: wil6210: debugfs: fix info leak in wil_write_file_wmi()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=074e865b37da55aa87baa16d68b96896f85f8adb;p=linux.git

wifi: wil6210: debugfs: fix info leak in wil_write_file_wmi()

[ Upstream commit 7a4836560a6198d245d5732e26f94898b12eb760 ]

The simple_write_to_buffer() function will succeed if even a single
byte is initialized.  However, we need to initialize the whole buffer
to prevent information leaks.  Just use memdup_user().

Fixes: ff974e408334 ("wil6210: debugfs interface to send raw WMI command")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/Ysg14NdKAZF/hcNG@kili
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index 4c944e595978b..c6f8254cb21d6 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -1012,18 +1012,12 @@ static ssize_t wil_write_file_wmi(struct file *file, const char __user *buf,
 	u16 cmdid;
 	int rc, rc1;
 
-	if (cmdlen < 0)
+	if (cmdlen < 0 || *ppos != 0)
 		return -EINVAL;
 
-	wmi = kmalloc(len, GFP_KERNEL);
-	if (!wmi)
-		return -ENOMEM;
-
-	rc = simple_write_to_buffer(wmi, len, ppos, buf, len);
-	if (rc < 0) {
-		kfree(wmi);
-		return rc;
-	}
+	wmi = memdup_user(buf, len);
+	if (IS_ERR(wmi))
+		return PTR_ERR(wmi);
 
 	cmd = (cmdlen > 0) ? &wmi[1] : NULL;
 	cmdid = le16_to_cpu(wmi->command_id);