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@rowland.harvard.edu Signed-off-by: Hangyu Hua hbh25y@gmail.com Link: https://lore.kernel.org/r/20211231172138.7993-2-hbh25y@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: stable@vger.kernel.org #4.4+ --- drivers/usb/gadget/legacy/inode.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index eaad03c0252f..25c8809e0a38 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1875,8 +1875,8 @@ 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) { - kfree (dev->buf); - dev->buf = NULL; + spin_lock_irq(&dev->lock); + goto fail; } else { /* at this point "good" hardware has for the first time * let the USB the host see us. alternatively, if users @@ -1893,6 +1893,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) return value;
fail: + dev->config = NULL; + dev->hs_config = NULL; + dev->dev = NULL; spin_unlock_irq (&dev->lock); pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev); kfree (dev->buf);