Messages in this thread | | | Subject | Re: [PATCH] staging: comedi: drivers: prevent memory leak | From | Ian Abbott <> | Date | Tue, 17 Sep 2019 11:13:15 +0100 |
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On 17/09/2019 07:33, Dan Carpenter wrote: > On Mon, Sep 16, 2019 at 09:41:43PM -0500, Navid Emamdoost wrote: >> In das1800_attach, the buffer allocated via kmalloc_array needs to be >> released if an error happens. >> >> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com> > > Commedit calls ->detach() if the ->attach() fails so this patch would > lead to a double free. See comedi_device_attach(): > > drivers/staging/comedi/drivers.c > 983 } > 984 if (!driv->attach) { > 985 /* driver does not support manual configuration */ > 986 dev_warn(dev->class_dev, > 987 "driver '%s' does not support attach using comedi_config\n", > 988 driv->driver_name); > 989 module_put(driv->module); > 990 ret = -EIO; > 991 goto out; > 992 } > 993 dev->driver = driv; > 994 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr > 995 : dev->driver->driver_name; > 996 ret = driv->attach(dev, it); > ^^^^^^^^^^^^^^^^^^^^^ > 997 if (ret >= 0) > 998 ret = comedi_device_postconfig(dev); > 999 if (ret < 0) { > 1000 comedi_device_detach(dev); > ^^^^^^^^^^^^^^^^^^^^^^^^^ > > 1001 module_put(driv->module); > 1002 } > 1003 /* On success, the driver module count has been incremented. */
Yes, everything should be freed properly by comedi_device_detach(). From comedi_device_detach(), some of the stuff is freed by dev->driver->detach(), and the remainder is freed by comedi_device_detach_cleanup().
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