staging: comedi: Fix comedi_device refcnt leak in comedi_open

comedi_open() invokes comedi_dev_get_from_minor(), which returns a
reference of the COMEDI device to "dev" with increased refcount.

When comedi_open() returns, "dev" becomes invalid, so the refcount
should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
comedi_open(). When "cfp" allocation is failed, the refcnt increased by
comedi_dev_get_from_minor() is not decreased, causing a refcnt leak.

Fix this issue by calling comedi_dev_put() on this error path when "cfp"
allocation is failed.

Fixes: 20f083c07565 ("staging: comedi: prepare support for per-file read and write subdevices")
Signed-off-by: Xiyu Yang <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Xin Tan <[email protected]>
Signed-off-by: Ian Abbott <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions