diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2026-01-28 15:00:10 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-11 14:29:51 +0200 |
| commit | d07d97ca4f7fac467cdcf4a012690853958b7e89 (patch) | |
| tree | 493181db99685c1e3712ee878b63e8e952e15e0d | |
| parent | 83134a7a176ce5b4b19b6edecf4360e8d98d1a5a (diff) | |
comedi: ni_atmio16d: Fix invalid clean-up after failed attach
commit 101ab946b79ad83b36d5cfd47de587492a80acf0 upstream.
If the driver's COMEDI "attach" handler function (`atmio16d_attach()`)
returns an error, the COMEDI core will call the driver's "detach"
handler function (`atmio16d_detach()`) to clean up. This calls
`reset_atmio16d()` unconditionally, but depending on where the error
occurred in the attach handler, the device may not have been
sufficiently initialized to call `reset_atmio16d()`. It uses
`dev->iobase` as the I/O port base address and `dev->private` as the
pointer to the COMEDI device's private data structure. `dev->iobase`
may still be set to its initial value of 0, which would result in
undesired writes to low I/O port addresses. `dev->private` may still be
`NULL`, which would result in null pointer dereferences.
Fix `atmio16d_detach()` by checking that `dev->private` is valid
(non-null) before calling `reset_atmio16d()`. This implies that
`dev->iobase` was set correctly since that is set up before
`dev->private`.
Fixes: 2323b276308a ("Staging: comedi: add ni_at_atmio16d driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260128150011.5006-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/comedi/drivers/ni_atmio16d.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/comedi/drivers/ni_atmio16d.c b/drivers/comedi/drivers/ni_atmio16d.c index e5e7cc423c87..b057b3b3582e 100644 --- a/drivers/comedi/drivers/ni_atmio16d.c +++ b/drivers/comedi/drivers/ni_atmio16d.c @@ -698,7 +698,8 @@ static int atmio16d_attach(struct comedi_device *dev, static void atmio16d_detach(struct comedi_device *dev) { - reset_atmio16d(dev); + if (dev->private) + reset_atmio16d(dev); comedi_legacy_detach(dev); } |