dev->config and dev->hs_config and dev->dev need to be cleaned if
dev_config fails to avoid UAF.
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
---
drivers/usb/gadget/legacy/inode.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index eaad03c0252f..d2e88f3b9131 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1847,7 +1847,7 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
total = le16_to_cpu(dev->hs_config->wTotalLength);
if (!is_valid_config(dev->hs_config, total) ||
total > length - USB_DT_DEVICE_SIZE)
- goto fail;
+ goto fail1;
kbuf += total;
length -= total;
} else {
@@ -1858,12 +1858,12 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
/* device descriptor (tweaked for paranoia) */
if (length != USB_DT_DEVICE_SIZE)
- goto fail;
+ goto fail1;
dev->dev = (void *)kbuf;
if (dev->dev->bLength != USB_DT_DEVICE_SIZE
|| dev->dev->bDescriptorType != USB_DT_DEVICE
|| dev->dev->bNumConfigurations != 1)
- goto fail;
+ goto fail2;
dev->dev->bcdUSB = cpu_to_le16 (0x0200);
/* triggers gadgetfs_bind(); then we can enumerate. */
@@ -1875,6 +1875,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
value = usb_gadget_probe_driver(&gadgetfs_driver);
if (value != 0) {
+ dev->dev = NULL;
+ dev->hs_config = NULL;
+ dev->config = NULL;
kfree (dev->buf);
dev->buf = NULL;
} else {
@@ -1892,7 +1895,12 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
}
return value;
+fail2:
+ dev->dev = NULL;
+fail1:
+ dev->hs_config = NULL;
fail:
+ dev->config = NULL;
spin_unlock_irq (&dev->lock);
pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
kfree (dev->buf);
--
2.25.1
