[PATCH 5.10 231/545] wifi: wil6210: debugfs: fix info leak in wil_write_file_wmi()

Greg Kroah-Hartman
2022-08-19T16:12:42Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ 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>
---
drivers/net/wireless/ath/wil6210/debugfs.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index 2d618f90afa7..58c98e58bccb 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);
--
2.35.1