Messages in this thread | | | Date | Wed, 23 Mar 2022 16:47:39 +0100 | From | Christoph Hellwig <> | Subject | Re: [scsi] 6aded12b10: kernel_BUG_at_mm/usercopy.c |
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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.
> 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).
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