On Fri, Oct 02, 2015 at 06:47:35PM +0530, Chandra S Gorentla wrote: > During the clean-up of the function, it is need to check if > errors occurred, not the memory pointer. > The bug here is that we have a use after free on the success path. It should have been mentioned in the changelog. Anyway, this patch is buggy. If result == -EFAULT then it will crash. Also this patch is really ugly. There is someone who is going to send a correct fix (just add a return 0). This driver usese "do everything" style error handling. It is a bug prone anti-pattern because doing everything is more complicated than doing one thing. You can easily see it is bug prone, because it made you introduce a bug, right? Instead the error handling should look like this: return 0; err_free_msg: kfree(pstrMessage); return ret; There are no error paths where we need to free "pstrMessage->pvBuffer" but if we were to add one it would look like this: return 0; err_pvbuffer: kfree(pstrMessage->pvBuffer); err_msg: kfree(pstrMessage); return ret; This is a minimal, uncomplicated, no indenting, no if statement way of unwinding. regards, dan carpenter _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
