diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2012-10-03 16:25:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-31 10:09:59 -0700 |
| commit | d136f0fd47d9953139381c8af74976de86eeb224 (patch) | |
| tree | f2d23633a2c794b3a63d33b259c3163d20bee186 /drivers | |
| parent | 88d5e653e2282bda43459dd577f3841f6ef140bf (diff) | |
staging: comedi: das08: fix possible NULL deref during detach
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 <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | 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 67a914a10b5..d893e3b2048 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -1028,6 +1028,8 @@ static void __maybe_unused das08_detach(struct comedi_device *dev) 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)) { |