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path: root/drivers/usb/misc/yurex.c
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Diffstat (limited to 'drivers/usb/misc/yurex.c')
-rw-r--r--drivers/usb/misc/yurex.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index c640f98d20..9a0649d236 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -34,6 +34,8 @@
#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) },
@@ -401,7 +403,7 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
{
struct usb_yurex *dev;
int len = 0;
- char in_buffer[20];
+ char in_buffer[MAX_S64_STRLEN];
unsigned long flags;
dev = file->private_data;
@@ -412,14 +414,16 @@ 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_irqsave(&dev->lock, flags);
- len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
+ scnprintf(in_buffer, MAX_S64_STRLEN, "%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);
}