diff options
| author |   Ian Abbott <abbotti@mev.co.uk> | 2012-10-03 16:25:18 +0100 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-22 11:46:35 -0700 |
| commit | 2db012bd40b889d8e5483d3daa07af04c4c109d8 (patch) | |
| tree | a5da369fb3beec3005faf761f2fa38ed2a3761f6 /drivers/staging | |
| parent | staging: comedi: amplc_pc236: fix invalid register access during detach (diff) | |
| download | linux-dev-2db012bd40b889d8e5483d3daa07af04c4c109d8.tar.xz linux-dev-2db012bd40b889d8e5483d3daa07af04c4c109d8.zip | |
staging: comedi: amplc_pc236: fix possible NULL deref during detach
`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: <stable@vger.kernel.org> # 3.6.x
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/comedi/drivers/amplc_pc236.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers/amplc_pc236.c b/drivers/staging/comedi/drivers/amplc_pc236.c index 36768b2b30ae..4e4f3c15df87 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) |