Revert "usb: yurex: Replace snprintf() with the safer scnprintf() variant"

commit 71c717cd8a2e180126932cc6851ff21c1d04d69a upstream.

This reverts commit 86b20af11e84c26ae3fde4dcc4f490948e3f8035.

This patch leads to passing 0 to simple_read_from_buffer()
as a fifth argument, turning the read method into a nop.
The change is fundamentally flawed, as it breaks the driver.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20241007094004.242122-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum 2024-10-07 11:39:47 +02:00 committed by Greg Kroah-Hartman
parent 8669bca53f
commit a7564b1606

View File

@ -34,8 +34,6 @@
#define YUREX_BUF_SIZE 8
#define YUREX_WRITE_TIMEOUT (HZ*2)
#define MAX_S64_STRLEN 20 /* {-}922337203685477580{7,8} */
/* table of devices that work with this driver */
static struct usb_device_id yurex_table[] = {
{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
@ -402,7 +400,8 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
{
struct usb_yurex *dev;
int len = 0;
char in_buffer[MAX_S64_STRLEN];
char in_buffer[20];
unsigned long flags;
dev = file->private_data;
@ -412,16 +411,14 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
return -ENODEV;
}
if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) {
mutex_unlock(&dev->io_mutex);
return -EIO;
}
spin_lock_irq(&dev->lock);
scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu);
spin_unlock_irq(&dev->lock);
spin_lock_irqsave(&dev->lock, flags);
len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
spin_unlock_irqrestore(&dev->lock, flags);
mutex_unlock(&dev->io_mutex);
if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
return -EIO;
return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
}