From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: Andi Kleen <ak@linux.intel.com> Cc: "Michael S. Tsirkin" <mst@redhat.com>, Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>, Borislav Petkov <bp@alien8.de>, x86@kernel.org, Bjorn Helgaas <bhelgaas@google.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Andreas Noever <andreas.noever@gmail.com>, Michael Jamet <michael.jamet@intel.com>, Yehezkel Bernat <YehezkelShB@gmail.com>, "Rafael J . Wysocki" <rafael@kernel.org>, Mika Westerberg <mika.westerberg@linux.intel.com>, Jonathan Corbet <corbet@lwn.net>, Jason Wang <jasowang@redhat.com>, Dan Williams <dan.j.williams@intel.com>, Kuppuswamy Sathyanarayanan <knsathya@kernel.org>, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, "Reshetova, Elena" <elena.reshetova@intel.com> Subject: Re: [PATCH v2 2/6] driver core: Add common support to skip probe for un-authorized devices Date: Fri, 1 Oct 2021 08:29:36 +0200 [thread overview] Message-ID: <YVaq0Hm8WHVY46xX@kroah.com> (raw) In-Reply-To: <bb27af8d-d4ba-fa70-8893-5b9939f9280a@linux.intel.com> On Thu, Sep 30, 2021 at 12:15:16PM -0700, Andi Kleen wrote: > > On 9/30/2021 10:23 AM, Greg Kroah-Hartman wrote: > > On Thu, Sep 30, 2021 at 10:17:09AM -0700, Andi Kleen wrote: > > > The legacy drivers could be fixed, but nobody really wants to touch them > > > anymore and they're impossible to test. > > Pointers to them? > > For example if you look over old SCSI drivers in drivers/scsi/*.c there is a > substantial number that has a module init longer than just registering a > driver. As a single example look at drivers/scsi/BusLogic.c Great, send patches to fix them up instead of adding new infrastructure to the kernel. It is better to remove code than add it. You can rip the ISA code out of that driver and then you will not have the issue anymore. Or again, just add that module to the deny list and never load it from userspace. > There were also quite a few platform drivers like this. Of course, platform drivers are horrible abusers of this. Just like the recent one submitted by Intel that would bind to any machine it was loaded on and did not actually do any hardware detection assuming that it owned the platform: https://lore.kernel.org/r/20210924213157.3584061-2-david.e.box@linux.intel.com So yes, some drivers are horrible, it is our job to catch that and fix it. If you don't want to load those drivers on your system, we have userspace solutions for that (you can have allow/deny lists there.) > > > The drivers that probe something that is not enumerated in a standard way > > > have no choice, it cannot be implemented in a different way. > > PCI devices are not enumerated in a standard way??? > > The pci devices are enumerated in a standard way, but typically the driver > also needs something else outside PCI that needs some other probing > mechanism. Like what? What PCI drivers need outside connections to control the hardware? > > > So instead we're using a "firewall" the prevents these drivers from doing > > > bad things by not allowing ioremap access unless opted in, and also do some > > > filtering on the IO ports The device filter is still the primary mechanism, > > > the ioremap filtering is just belts and suspenders for those odd cases. > > That's horrible, don't try to protect the kernel from itself. Just fix > > the drivers. > > I thought we had already established this last time we discussed it. > > That's completely impractical. We cannot harden thousands of drivers, > especially since it would be all wasted work since nobody will ever need > them in virtual guests. Even if we could harden them how would such a work > be maintained long term? Using a firewall and filtering mechanism is much > saner for everyone. I agree, you can not "harden" anything here. That is why I asked you to use the existing process that explicitly moves the model to userspace where a user can say "do I want this device to be controlled by the kernel or not" which then allows you to pick and choose what drivers you want to have in your system. You need to trust devices, and not worry about trusting drivers as you yourself admit :) The kernel's trust model is that once we bind to them, we trust almost all device types almost explicitly. If you wish to change that model, that's great, but it is a much larger discussion than this tiny patchset would require. thanks, greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: Andi Kleen <ak@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net>, Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>, Kuppuswamy Sathyanarayanan <knsathya@kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>, Michael Jamet <michael.jamet@intel.com>, linux-pci@vger.kernel.org, x86@kernel.org, virtualization@lists.linux-foundation.org, Yehezkel Bernat <YehezkelShB@gmail.com>, linux-kernel@vger.kernel.org, Andreas Noever <andreas.noever@gmail.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "Reshetova, Elena" <elena.reshetova@intel.com>, Bjorn Helgaas <bhelgaas@google.com>, Thomas Gleixner <tglx@linutronix.de>, linux-usb@vger.kernel.org, Mika Westerberg <mika.westerberg@linux.intel.com>, Dan Williams <dan.j.williams@intel.com>, "Rafael J . Wysocki" <rafael@kernel.org> Subject: Re: [PATCH v2 2/6] driver core: Add common support to skip probe for un-authorized devices Date: Fri, 1 Oct 2021 08:29:36 +0200 [thread overview] Message-ID: <YVaq0Hm8WHVY46xX@kroah.com> (raw) In-Reply-To: <bb27af8d-d4ba-fa70-8893-5b9939f9280a@linux.intel.com> On Thu, Sep 30, 2021 at 12:15:16PM -0700, Andi Kleen wrote: > > On 9/30/2021 10:23 AM, Greg Kroah-Hartman wrote: > > On Thu, Sep 30, 2021 at 10:17:09AM -0700, Andi Kleen wrote: > > > The legacy drivers could be fixed, but nobody really wants to touch them > > > anymore and they're impossible to test. > > Pointers to them? > > For example if you look over old SCSI drivers in drivers/scsi/*.c there is a > substantial number that has a module init longer than just registering a > driver. As a single example look at drivers/scsi/BusLogic.c Great, send patches to fix them up instead of adding new infrastructure to the kernel. It is better to remove code than add it. You can rip the ISA code out of that driver and then you will not have the issue anymore. Or again, just add that module to the deny list and never load it from userspace. > There were also quite a few platform drivers like this. Of course, platform drivers are horrible abusers of this. Just like the recent one submitted by Intel that would bind to any machine it was loaded on and did not actually do any hardware detection assuming that it owned the platform: https://lore.kernel.org/r/20210924213157.3584061-2-david.e.box@linux.intel.com So yes, some drivers are horrible, it is our job to catch that and fix it. If you don't want to load those drivers on your system, we have userspace solutions for that (you can have allow/deny lists there.) > > > The drivers that probe something that is not enumerated in a standard way > > > have no choice, it cannot be implemented in a different way. > > PCI devices are not enumerated in a standard way??? > > The pci devices are enumerated in a standard way, but typically the driver > also needs something else outside PCI that needs some other probing > mechanism. Like what? What PCI drivers need outside connections to control the hardware? > > > So instead we're using a "firewall" the prevents these drivers from doing > > > bad things by not allowing ioremap access unless opted in, and also do some > > > filtering on the IO ports The device filter is still the primary mechanism, > > > the ioremap filtering is just belts and suspenders for those odd cases. > > That's horrible, don't try to protect the kernel from itself. Just fix > > the drivers. > > I thought we had already established this last time we discussed it. > > That's completely impractical. We cannot harden thousands of drivers, > especially since it would be all wasted work since nobody will ever need > them in virtual guests. Even if we could harden them how would such a work > be maintained long term? Using a firewall and filtering mechanism is much > saner for everyone. I agree, you can not "harden" anything here. That is why I asked you to use the existing process that explicitly moves the model to userspace where a user can say "do I want this device to be controlled by the kernel or not" which then allows you to pick and choose what drivers you want to have in your system. You need to trust devices, and not worry about trusting drivers as you yourself admit :) The kernel's trust model is that once we bind to them, we trust almost all device types almost explicitly. If you wish to change that model, that's great, but it is a much larger discussion than this tiny patchset would require. thanks, greg k-h _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-10-01 6:29 UTC|newest] Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-30 1:05 [PATCH v2 0/6] Add device filter support Kuppuswamy Sathyanarayanan 2021-09-30 1:05 ` [PATCH v2 1/6] driver core: Move the "authorized" attribute from USB/Thunderbolt to core Kuppuswamy Sathyanarayanan 2021-09-30 1:42 ` Alan Stern 2021-09-30 1:42 ` Alan Stern 2021-09-30 1:55 ` Dan Williams 2021-09-30 1:55 ` Dan Williams 2021-09-30 2:38 ` Kuppuswamy, Sathyanarayanan 2021-09-30 4:59 ` Dan Williams 2021-09-30 4:59 ` Dan Williams 2021-09-30 9:05 ` Rafael J. Wysocki 2021-09-30 9:05 ` Rafael J. Wysocki 2021-09-30 14:59 ` Alan Stern 2021-09-30 14:59 ` Alan Stern 2021-09-30 15:25 ` Dan Williams 2021-09-30 15:25 ` Dan Williams 2021-09-30 11:19 ` Yehezkel Bernat 2021-09-30 15:28 ` Dan Williams 2021-09-30 15:28 ` Dan Williams 2021-09-30 18:25 ` Yehezkel Bernat 2021-09-30 19:04 ` Dan Williams 2021-09-30 19:04 ` Dan Williams 2021-09-30 19:50 ` Kuppuswamy, Sathyanarayanan 2021-09-30 20:23 ` Dan Williams 2021-09-30 20:23 ` Dan Williams 2021-09-30 1:05 ` [PATCH v2 2/6] driver core: Add common support to skip probe for un-authorized devices Kuppuswamy Sathyanarayanan 2021-09-30 10:59 ` Michael S. Tsirkin 2021-09-30 10:59 ` Michael S. Tsirkin 2021-09-30 13:52 ` Greg Kroah-Hartman 2021-09-30 13:52 ` Greg Kroah-Hartman 2021-09-30 14:38 ` Michael S. Tsirkin 2021-09-30 14:38 ` Michael S. Tsirkin 2021-09-30 14:49 ` Greg Kroah-Hartman 2021-09-30 14:49 ` Greg Kroah-Hartman 2021-09-30 15:00 ` Michael S. Tsirkin 2021-09-30 15:00 ` Michael S. Tsirkin 2021-09-30 15:22 ` Greg Kroah-Hartman 2021-09-30 15:22 ` Greg Kroah-Hartman 2021-09-30 17:17 ` Andi Kleen 2021-09-30 17:17 ` Andi Kleen 2021-09-30 17:23 ` Greg Kroah-Hartman 2021-09-30 17:23 ` Greg Kroah-Hartman 2021-09-30 19:15 ` Andi Kleen 2021-09-30 19:15 ` Andi Kleen 2021-10-01 6:29 ` Greg Kroah-Hartman [this message] 2021-10-01 6:29 ` Greg Kroah-Hartman 2021-10-01 15:51 ` Alan Stern 2021-10-01 15:51 ` Alan Stern 2021-10-01 15:56 ` Andi Kleen 2021-10-01 15:56 ` Andi Kleen 2021-09-30 14:43 ` Alan Stern 2021-09-30 14:43 ` Alan Stern 2021-09-30 14:48 ` Michael S. Tsirkin 2021-09-30 14:48 ` Michael S. Tsirkin 2021-09-30 15:32 ` Alan Stern 2021-09-30 15:32 ` Alan Stern 2021-09-30 15:52 ` Michael S. Tsirkin 2021-09-30 15:52 ` Michael S. Tsirkin 2021-09-30 14:58 ` Michael S. Tsirkin 2021-09-30 14:58 ` Michael S. Tsirkin 2021-09-30 15:35 ` Alan Stern 2021-09-30 15:35 ` Alan Stern 2021-09-30 15:59 ` Michael S. Tsirkin 2021-09-30 15:59 ` Michael S. Tsirkin 2021-09-30 19:23 ` Andi Kleen 2021-09-30 19:23 ` Andi Kleen 2021-09-30 20:44 ` Alan Stern 2021-09-30 20:44 ` Alan Stern 2021-09-30 20:52 ` Dan Williams 2021-09-30 20:52 ` Dan Williams 2021-10-01 1:41 ` Alan Stern 2021-10-01 1:41 ` Alan Stern 2021-10-01 2:20 ` Dan Williams 2021-10-01 2:20 ` Dan Williams 2021-09-30 21:12 ` Andi Kleen 2021-09-30 21:12 ` Andi Kleen 2021-09-30 1:05 ` [PATCH v2 3/6] driver core: Allow arch to initialize the authorized attribute Kuppuswamy Sathyanarayanan 2021-09-30 1:05 ` [PATCH v2 4/6] virtio: Initialize authorized attribute for confidential guest Kuppuswamy Sathyanarayanan 2021-09-30 11:03 ` Michael S. Tsirkin 2021-09-30 11:03 ` Michael S. Tsirkin 2021-09-30 13:36 ` Dan Williams 2021-09-30 13:36 ` Dan Williams 2021-09-30 13:49 ` Greg Kroah-Hartman 2021-09-30 13:49 ` Greg Kroah-Hartman 2021-09-30 15:18 ` Kuppuswamy, Sathyanarayanan 2021-09-30 15:20 ` Michael S. Tsirkin 2021-09-30 15:20 ` Michael S. Tsirkin 2021-09-30 15:23 ` Kuppuswamy, Sathyanarayanan 2021-09-30 15:23 ` Greg Kroah-Hartman 2021-09-30 15:23 ` Greg Kroah-Hartman 2021-09-30 19:04 ` Kuppuswamy, Sathyanarayanan 2021-09-30 19:16 ` Kuppuswamy, Sathyanarayanan 2021-09-30 19:30 ` Andi Kleen 2021-09-30 19:30 ` Andi Kleen 2021-09-30 19:40 ` Kuppuswamy, Sathyanarayanan 2021-10-01 7:03 ` Greg Kroah-Hartman 2021-10-01 7:03 ` Greg Kroah-Hartman 2021-10-01 15:49 ` Andi Kleen 2021-10-01 15:49 ` Andi Kleen 2021-10-02 11:04 ` Michael S. Tsirkin 2021-10-02 11:04 ` Michael S. Tsirkin 2021-10-02 11:14 ` Greg Kroah-Hartman 2021-10-02 11:14 ` Greg Kroah-Hartman 2021-10-02 14:20 ` Andi Kleen 2021-10-02 14:20 ` Andi Kleen 2021-10-02 14:44 ` Greg Kroah-Hartman 2021-10-02 14:44 ` Greg Kroah-Hartman 2021-10-02 18:40 ` Michael S. Tsirkin 2021-10-02 18:40 ` Michael S. Tsirkin 2021-10-03 6:40 ` Greg Kroah-Hartman 2021-10-03 6:40 ` Greg Kroah-Hartman 2021-10-04 21:04 ` Dan Williams 2021-10-04 21:04 ` Dan Williams 2021-10-01 16:13 ` Dan Williams 2021-10-01 16:13 ` Dan Williams 2021-10-01 16:45 ` Alan Stern 2021-10-01 16:45 ` Alan Stern 2021-10-01 18:09 ` Dan Williams 2021-10-01 18:09 ` Dan Williams 2021-10-01 19:00 ` Alan Stern 2021-10-01 19:00 ` Alan Stern 2021-10-01 19:45 ` Kuppuswamy, Sathyanarayanan 2021-10-01 19:57 ` Dan Williams 2021-10-01 19:57 ` Dan Williams 2021-10-04 5:16 ` Mika Westerberg 2021-10-05 22:33 ` Dan Williams 2021-10-05 22:33 ` Dan Williams 2021-10-06 5:45 ` Greg Kroah-Hartman 2021-10-06 5:45 ` Greg Kroah-Hartman 2021-09-30 19:25 ` Andi Kleen 2021-09-30 19:25 ` Andi Kleen 2021-09-30 1:05 ` [PATCH v2 5/6] x86/tdx: Add device filter support for x86 TDX guest platform Kuppuswamy Sathyanarayanan 2021-09-30 1:05 ` [PATCH v2 6/6] PCI: Initialize authorized attribute for confidential guest Kuppuswamy Sathyanarayanan
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=YVaq0Hm8WHVY46xX@kroah.com \ --to=gregkh@linuxfoundation.org \ --cc=YehezkelShB@gmail.com \ --cc=ak@linux.intel.com \ --cc=andreas.noever@gmail.com \ --cc=bhelgaas@google.com \ --cc=bp@alien8.de \ --cc=corbet@lwn.net \ --cc=dan.j.williams@intel.com \ --cc=elena.reshetova@intel.com \ --cc=jasowang@redhat.com \ --cc=knsathya@kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pci@vger.kernel.org \ --cc=linux-usb@vger.kernel.org \ --cc=michael.jamet@intel.com \ --cc=mika.westerberg@linux.intel.com \ --cc=mingo@redhat.com \ --cc=mst@redhat.com \ --cc=rafael@kernel.org \ --cc=sathyanarayanan.kuppuswamy@linux.intel.com \ --cc=tglx@linutronix.de \ --cc=virtualization@lists.linux-foundation.org \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.