This is a note to let you know that I've just added the patch titled wifi: wil6210: debugfs: fix info leak in wil_write_file_wmi() to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-wil6210-debugfs-fix-info-leak-in-wil_write_file.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 29f6d80aecb279597fc80ebee021d4556c4be453 Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Fri Jul 15 13:35:18 2022 +0300 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@xxxxxxxxxx> Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx> Link: https://lore.kernel.org/r/Ysg14NdKAZF/hcNG@kili Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c index 55a809cb3105..675b2829b4c7 100644 --- a/drivers/net/wireless/ath/wil6210/debugfs.c +++ b/drivers/net/wireless/ath/wil6210/debugfs.c @@ -1004,18 +1004,12 @@ 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);