`pc236_detach()` is called by the comedi core to clean up if either `pc236_attach()` or `pc236_attach_pci()` returns an error. It sets `thisboard` to the return value of `comedi_board(dev)` and assumes it is non-null. This is a valid assumption if `pc236_attach()` fails, but not if `pc236_attach_pci()` fails, leading to a possible NULL pointer dereference.
Check `thisboard` at the top of `pc236_detach()` and return early if it is `NULL`. This is okay because the only other thing that could have been allocated is `dev->private` and that is freed by the comedi core, not by this function. Cc: <[email protected]> # 3.6.x Signed-off-by: Ian Abbott <[email protected]> --- drivers/staging/comedi/drivers/amplc_pc236.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/staging/comedi/drivers/amplc_pc236.c b/drivers/staging/comedi/drivers/amplc_pc236.c index 36768b2..4e4f3c1 100644 --- a/drivers/staging/comedi/drivers/amplc_pc236.c +++ b/drivers/staging/comedi/drivers/amplc_pc236.c @@ -574,6 +574,8 @@ static void pc236_detach(struct comedi_device *dev) { const struct pc236_board *thisboard = comedi_board(dev); + if (!thisboard) + return; if (dev->iobase) pc236_intr_disable(dev); if (dev->irq) -- 1.7.12 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
