Re: [PATCH RFC v1b] firewire: cdev: prevent kernel stack leaking into ioctl arguments

2014-11-11 Thread Clemens Ladisch
Stefan Richter wrote: > This fix simply always null-initializes the entire ioctl argument buffer > regardless of the actual length of expected user input. That is, a > runtime overhead of memset(..., 40) is added to each firewirew-cdev > ioctl() call. This part of the stack is most likely to be a

[PATCH RFC v1b] firewire: cdev: prevent kernel stack leaking into ioctl arguments

2014-11-11 Thread Stefan Richter
Found by the UC-KLEE tool: A user could supply less input to firewire-cdev ioctls than write- or write/read-type ioctl handlers expect. The handlers used data from uninitialized kernel stack then. This could partially leak back to the user if the kernel subsequently generated fw_cdev_event_'s (t