On Wed, Sep 18, 2019 at 5:35 PM Steffen Maier [off-list ref] wrote:

scsi_cmd_ioctl() had hdr as on stack auto variable and called
copy_{from,to}_user with the address operator &hdr and sizeof(hdr).

After the refactoring, {get,put}_sg_io_hdr() takes a pointer &hdr.
So the copy_{from,to}_user within the new helper functions should
just take the given pointer argument hdr and sizeof(*hdr).

I saw -EINVAL from sg_io() done by /usr/lib/udev/scsi_id which could
in turn no longer whitelist SCSI disks for devicemapper multipath.

Signed-off-by: Steffen Maier <redacted>
Fixes: 4f45155c29fd ("compat_ioctl: reimplement SG_IO handling")
---

Arnd, I'm not sure about the sizeof(hdr32) change in the compat part in
put_sg_io_hdr().

This is for next, probably via Arnd's y2038/y2038,
and it fixes next-20190917 for me regarding SCSI generic.

Hi Steffen,

Sorry for the long delay. I ended up not sending my pull request for
v5.4, so the bug is not there. I have now rebased my branch
on top of v5.4-rc2 and plan to send it for the v5.5 merge window.

I have folded your bugfix into my original patch, hope that's ok with
you. Tomorrow's linux-next should be fixed.

    Arnd