From: Hangyu Hua <hbh25y@xxxxxxxxx> commit 501e38a5531efbd77d5c73c0ba838a889bfc1d74 upstream. 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> Link: https://lore.kernel.org/r/20211231172138.7993-3-hbh25y@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/legacy/inode.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1877,8 +1877,8 @@ dev_config (struct file *fd, const char 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 @@ -1895,6 +1895,9 @@ dev_config (struct file *fd, const char 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);
