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Commit 3955dfa8216f712bc204a5ad2f4e51efff252fde

Authored by Ian Abbott
Committed by Greg Kroah-Hartman
1 parent 06cdff8a59
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

staging: comedi: bug-fix NULL pointer dereference on failed attach 

Commit dcd7b8bd63cb81c5b973bf86510ca3c80bbbd162 ("staging: comedi: put
module _after_ detach" by myself) reversed a couple of calls in
`comedi_device_attach()` when recovering from an error returned by the
low-level driver's 'attach' handler.  Unfortunately, that introduced a
NULL pointer dereference bug as `dev->driver` is NULL after the call to
`comedi_device_detach()`.   We still have a pointer to the low-level
comedi driver structure in the `driv` variable, so use that instead.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 1 changed file with 1 additions and 1 deletions Side-by-side Diff

drivers/staging/comedi/drivers.c
Diff comments   View file @ 3955dfa
... ... @@ -482,7 +482,7 @@
482 482 ret = comedi_device_postconfig(dev);
483 483 if (ret < 0) {
484 484 comedi_device_detach(dev);
485   - module_put(dev->driver->module);
  485 + module_put(driv->module);
486 486 }
487 487 /* On success, the driver module count has been incremented. */
488 488 return ret;