On Tue, Nov 22, 2016 at 8:30 PM, Ewan D. Milne <emilne@xxxxxxxxxx> wrote: > > I see the behavior (zero byte) on the 4.4.34, 4.5.7, 4.6.7, and 4.7.10 > -stable kernels. But not (of course) on 4.8.10 -stable. > > It doesn't look like the sg driver, might be something in the mmap code? A kernel guy colleague suggested to look at copy_from_user / copy_to_user code. It was changed in 4.8 It was OK with 3.13 (Ubuntu 14.04) but from some kernel (prior or equal to 4.4) until 4.7 we see the bug. It was somehow fixed at 4.8. In order to fully understand what happened, there are two changes to find. They might not even be related. Thanks! Eyal -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html