From dd0eed9e165b1a6292f49e622e3dd0b7d99b106d Mon Sep 17 00:00:00 2001 From: Lovekesh Solanki Date: Tue, 25 Aug 2026 22:43:43 +0530 Subject: [PATCH] USB: gadget: fix NULL pointer dereference in gadget_dev_ioctl() gadget_dev_ioctl() reads dev->gadget before acquiring dev->lock, but dev->state is checked after acquiring the lock. Therefore a concurrent bind can change the device state between these operations, which can leave ioctl with a stale NULL gadget pointer and causing a NULL pointer dereference at gadget->ops->ioctl. Read dev->gadget while holding dev->lock so that the gadget pointer and device state are sampled consistently. Cc: stable Reported-by: Eulgyu Kim Link: https://lore.kernel.org/all/20260824113510.1141236-1-jjy600901@snu.ac.kr/ Reported-by: Jaeyoung Chung Link: https://lore.kernel.org/all/20260824113510.1141236-1-jjy600901@snu.ac.kr/ Signed-off-by: Lovekesh Solanki Reviewed-by: Alan Stern Link: https://patch.msgid.link/20260825171343.459630-1-lovekeshsolanki00@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/legacy/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index db961aaa3740..67c6ffaf4f72 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1260,10 +1260,11 @@ ep0_poll (struct file *fd, poll_table *wait) static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value) { struct dev_data *dev = fd->private_data; - struct usb_gadget *gadget = dev->gadget; + struct usb_gadget *gadget; long ret = -ENOTTY; spin_lock_irq(&dev->lock); + gadget = dev->gadget; if (dev->state == STATE_DEV_OPENED || dev->state == STATE_DEV_UNBOUND) { /* Not bound to a UDC */