On Wed, Mar 23, 2022 at 04:47:39PM +0100, Christoph Hellwig wrote: > On Wed, Mar 23, 2022 at 08:40:30AM -0700, Kees Cook wrote: > > Regardless, I'm concerned that disabling PAGESPAN will just uncover > > further checks, though. Where is allocation happening? The check is here: > > blk_mq_alloc_rqs, using alloc_pages_node. This hasn't actually changed > with this comment. Just the size of the allocation shrunk, probably > leading to the span of pages. Okay, the page allocator _should_ be fine for that. In the mean time, lkp should probably just disable PAGESPAN. > > I *think* the allocation is happening in scsi_ioctl_reset()? But that's > > a plain kmalloc(), so I'm not sure why PAGESPAN would have tripped... > > are there other allocation paths? > > scsi_ioctl_reset is the odd one out and does also allocate a request, > but that request is never used for user copies (and that whole hacky > side path needs to go away, there is a huge series that needs to be > finished to sort this out). Gotcha! -- Kees Cook
