Re: [PATCH] mpt3sas_ctl: fix double-fetch bug in _ctl_ioctl_main()

From: Martin K. Petersen
Date: Wed May 29 2019 - 22:25:44 EST


> In _ctl_ioctl_main(), 'ioctl_header' is fetched the first time from
> userspace. 'ioctl_header.ioc_number' is then checked. The legal result
> is saved to 'ioc'. Then, in condition MPT3COMMAND, the whole struct is
> fetched again from the userspace. Then _ctl_do_mpt_command() is called,
> 'ioc' and 'karg' as inputs.
> However, a malicious user can change the 'ioc_number' between the two
> fetches, which will cause a potential security issues. Moreover, a
> malicious user can provide a valid 'ioc_number' to pass the check in
> first fetch, and then modify it in the second fetch.
> To fix this, we need to recheck the 'ioc_number' in the second fetch.

Applied to 5.3/scsi-queue, thanks.

Martin K. Petersen Oracle Linux Engineering