commit: ee280d134f2e05e0172369a53fbe202dbfc527fa From: Ian Abbott <[email protected]> Date: Wed, 3 Oct 2012 16:25:20 +0100 Subject: staging: comedi: das08: fix possible NULL deref during detach
`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. Cc: <[email protected]> # 3.6.x Signed-off-by: Ian Abbott <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/staging/comedi/drivers/das08.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index 5fd21fa..c304528 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -846,6 +846,8 @@ static void __maybe_unused das08_detach(struct comedi_device *dev) { const struct das08_board_struct *thisboard = comedi_board(dev); + if (!thisboard) + return; das08_common_detach(dev); if (is_isa_board(thisboard)) { if (dev->iobase) -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
