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| author | Ian Abbott <abbotti@mev.co.uk> | 2012-10-03 16:25:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-22 11:46:35 -0700 |
| commit | ee280d134f2e05e0172369a53fbe202dbfc527fa (patch) | |
| tree | 5f2056a8137a341ad42e17d0f44657ee6c8fa2de /drivers/staging | |
| parent | 1d1171ffda585c1cab7bd7cf4bd8f8fd5923fb4a (diff) | |
| download | lwn-ee280d134f2e05e0172369a53fbe202dbfc527fa.tar.gz lwn-ee280d134f2e05e0172369a53fbe202dbfc527fa.zip | |
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: <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/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 5fd21fa6c1c7..c304528cfb13 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) |