Fix possible NULL pointer dereference introduced in
commit
219580e (usb: f_fs: check quirk to pad epout
buf size when not aligned to maxpacketsize)
In cases we do wait with:
wait_event_interruptible(epfile->wait, (ep = epfile->ep));
for endpoint to be enabled, functionfs_bind() has not been called yet
and epfile->ffs->gadget is still NULL and the automatic variable 'gadget'
has been initialized with NULL at the point of its definition.
Later on it is used as a parameter to:
usb_ep_align_maybe(gadget, ep->ep, len)
which in turn dereferences it.
This patch fixes it by moving the actual assignment to the local 'gadget'
variable after the potential waiting has completed.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
char __user *buf, size_t len, int read)
{
struct ffs_epfile *epfile = file->private_data;
- struct usb_gadget *gadget = epfile->ffs->gadget;
struct ffs_ep *ep;
char *data = NULL;
ssize_t ret, data_len;
/* Allocate & copy */
if (!halt) {
+ /*
+ * if we _do_ wait above, the epfile->ffs->gadget might be NULL
+ * before the waiting completes, so do not assign to 'gadget' earlier
+ */
+ struct usb_gadget *gadget = epfile->ffs->gadget;
+
/*
* Controller may require buffer size to be aligned to
* maxpacketsize of an out endpoint.