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.
Signed-off-by: Gen Zhang <[email protected]>
---
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index b2bb47c..5181c03 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
break;
}
+ if (karg.hdr.ioc_number != ioctl_header.ioc_number) {
+ ret = -EINVAL;
+ break;
+ }
if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) {
uarg = arg;
ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf);
Please consider this patch as Ack-by: Suganath Prabu S
<[email protected]>
Thanks,
Suganath.
On Mon, May 27, 2019 at 6:27 AM Gen Zhang <[email protected]> wrote:
>
> 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.
>
> Signed-off-by: Gen Zhang <[email protected]>
> ---
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> index b2bb47c..5181c03 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> @@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
> break;
> }
>
> + if (karg.hdr.ioc_number != ioctl_header.ioc_number) {
> + ret = -EINVAL;
> + break;
> + }
> if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) {
> uarg = arg;
> ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf);
On Tue, May 28, 2019 at 11:44:35AM +0530, Suganath Prabu Subramani wrote:
> Please consider this patch as Ack-by: Suganath Prabu S
> <[email protected]>
>
> Thanks,
> Suganath.
>
>
> On Mon, May 27, 2019 at 6:27 AM Gen Zhang <[email protected]> wrote:
> >
> > 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.
> >
> > Signed-off-by: Gen Zhang <[email protected]>
> > ---
> > diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> > index b2bb47c..5181c03 100644
> > --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> > +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
> > @@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
> > break;
> > }
> >
> > + if (karg.hdr.ioc_number != ioctl_header.ioc_number) {
> > + ret = -EINVAL;
> > + break;
> > + }
> > if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) {
> > uarg = arg;
> > ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf);
Thanks for your reply, Suganath.
Thanks
Gen