3.6-stable review patch. If anyone has any objections, please let me know.
------------------ From: Ian Abbott <abbo...@mev.co.uk> commit ee280d134f2e05e0172369a53fbe202dbfc527fa upstream. `das08_detach()` is called by the comedi core to clean up if either `das08_attach()` or `das08_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 `das08_attach()` fails, but not if `das08_attach_pci()` fails, leading to a possible NULL pointer dereference. Check `thisboard` at the top of `das08_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. Signed-off-by: Ian Abbott <abbo...@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/staging/comedi/drivers/das08.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -1028,6 +1028,8 @@ static void __maybe_unused das08_detach( const struct das08_board_struct *thisboard = comedi_board(dev); struct das08_private_struct *devpriv = dev->private; + if (!thisboard) + return; das08_common_detach(dev); if (IS_ENABLED(CONFIG_COMEDI_DAS08_ISA) && (thisboard->bustype == isa || thisboard->bustype == pc104)) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/