From: "Arnd Bergmann" <arnd@arndb.de>
To: "Artur Rojek" <contact@artur-rojek.eu>,
"Geert Uytterhoeven" <geert@linux-m68k.org>
Cc: linux-fbdev@vger.kernel.org, linux-ia64@vger.kernel.org,
dri-devel@lists.freedesktop.org,
"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
sparclinux@vger.kernel.org, WANG Xuerui <kernel@xen0n.name>,
Sam Ravnborg <sam@ravnborg.org>,
Linux-Arch <linux-arch@vger.kernel.org>,
kernel test robot <lkp@intel.com>, Helge Deller <deller@gmx.de>,
Huacai Chen <chenhuacai@kernel.org>,
Javier Martinez Canillas <javierm@redhat.com>,
Vineet Gupta <vgupta@kernel.org>,
linux-snps-arc@lists.infradead.org, suijingfeng@loongson.cn,
linux-m68k@lists.linux-m68k.org, loongarch@lists.linux.dev,
oe-kbuild-all@lists.linux.dev,
linux-arm-kernel@lists.infradead.org,
linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Zimmermann <tzimmermann@suse.de>,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h>
Date: Thu, 11 May 2023 15:40:28 +0200 [thread overview]
Message-ID: <d27e359c-1ea3-4d08-b124-e794fd372b28@app.fastmail.com> (raw)
In-Reply-To: <9c4be198444e9987c826c87b592e9dc6@artur-rojek.eu>
On Thu, May 11, 2023, at 15:22, Artur Rojek wrote:
> On 2023-05-11 14:35, Geert Uytterhoeven wrote:
>>
>> CC Artur, who's working on HP Jornada 680.
> Thanks for CC'ing me - I faced this exact issue while working on my
> (still not upstreamed) hd6446x PCMCIA controller driver. The PCMCIA
> subsystem uses `inb/outb`, which expect the `sh_io_port_base` to be set
> to something else than the default `-1`. At first I tried to set it to
> `0xa0000000`, so that all I/O goes through the fixed, non-cacheable P2
> area. That however broke some other driver code (I had no time to debug
> which one). Eventually I ended up taking a suggestion from a MIPS PCMCIA
> driver [1] and simply substract the broken `sh_io_port_base` address
> from `HD64461_IOBASE`, as the base for `socket.io_offset`. This way all
> the PCMCIA `inb/outb` accesses are absolute, no matter what the
> `sh_io_port_base` is set to. This of course is a very ugly solution and
> we should instead fix the root cause of this mess. I will have a better
> look at this patch set and the problem at hand at a later date.
>
> Cheers,
> Artur
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pcmcia/db1xxx_ss.c?h=v6.4-rc1#n527
I think the best fix would be to change all those drivers away
from using inb/outb to readb/writeb, except when they access the
actual PCMCIA I/O space behind the bridge.
On most of the modern architectures, inb(addr) now turns into
approximately readb(PCI_IOBASE + addr), with a bit of extra
logic to deal with endianess and barrier semantics.
PCI_IOBASE in turn tends to be a hardcoded virtual address
to which the physical I/O space window gets mapped during
early boot, though you can also #define it to sh_io_port_base
if you want to allocate the virtual address dynamically and
leave the existing logic unchanged.
Setting sh_io_port_base to zero however is a problem for any
driver that passes a small port number into it -- this then
turns into a user space pointer dereference, which is trivially
exploitable.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Artur Rojek" <contact@artur-rojek.eu>,
"Geert Uytterhoeven" <geert@linux-m68k.org>
Cc: "Thomas Zimmermann" <tzimmermann@suse.de>,
"kernel test robot" <lkp@intel.com>,
"Helge Deller" <deller@gmx.de>,
"Javier Martinez Canillas" <javierm@redhat.com>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Vineet Gupta" <vgupta@kernel.org>,
"Huacai Chen" <chenhuacai@kernel.org>,
"WANG Xuerui" <kernel@xen0n.name>,
"David S . Miller" <davem@davemloft.net>,
"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
"Sam Ravnborg" <sam@ravnborg.org>,
suijingfeng@loongson.cn, oe-kbuild-all@lists.linux.dev,
Linux-Arch <linux-arch@vger.kernel.org>,
linux-fbdev@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, linux-m68k@lists.linux-m68k.org,
loongarch@lists.linux.dev, sparclinux@vger.kernel.org,
linux-snps-arc@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h>
Date: Thu, 11 May 2023 15:40:28 +0200 [thread overview]
Message-ID: <d27e359c-1ea3-4d08-b124-e794fd372b28@app.fastmail.com> (raw)
In-Reply-To: <9c4be198444e9987c826c87b592e9dc6@artur-rojek.eu>
On Thu, May 11, 2023, at 15:22, Artur Rojek wrote:
> On 2023-05-11 14:35, Geert Uytterhoeven wrote:
>>
>> CC Artur, who's working on HP Jornada 680.
> Thanks for CC'ing me - I faced this exact issue while working on my
> (still not upstreamed) hd6446x PCMCIA controller driver. The PCMCIA
> subsystem uses `inb/outb`, which expect the `sh_io_port_base` to be set
> to something else than the default `-1`. At first I tried to set it to
> `0xa0000000`, so that all I/O goes through the fixed, non-cacheable P2
> area. That however broke some other driver code (I had no time to debug
> which one). Eventually I ended up taking a suggestion from a MIPS PCMCIA
> driver [1] and simply substract the broken `sh_io_port_base` address
> from `HD64461_IOBASE`, as the base for `socket.io_offset`. This way all
> the PCMCIA `inb/outb` accesses are absolute, no matter what the
> `sh_io_port_base` is set to. This of course is a very ugly solution and
> we should instead fix the root cause of this mess. I will have a better
> look at this patch set and the problem at hand at a later date.
>
> Cheers,
> Artur
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pcmcia/db1xxx_ss.c?h=v6.4-rc1#n527
I think the best fix would be to change all those drivers away
from using inb/outb to readb/writeb, except when they access the
actual PCMCIA I/O space behind the bridge.
On most of the modern architectures, inb(addr) now turns into
approximately readb(PCI_IOBASE + addr), with a bit of extra
logic to deal with endianess and barrier semantics.
PCI_IOBASE in turn tends to be a hardcoded virtual address
to which the physical I/O space window gets mapped during
early boot, though you can also #define it to sh_io_port_base
if you want to allocate the virtual address dynamically and
leave the existing logic unchanged.
Setting sh_io_port_base to zero however is a problem for any
driver that passes a small port number into it -- this then
turns into a user space pointer dereference, which is trivially
exploitable.
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Artur Rojek" <contact@artur-rojek.eu>,
"Geert Uytterhoeven" <geert@linux-m68k.org>
Cc: "Thomas Zimmermann" <tzimmermann@suse.de>,
"kernel test robot" <lkp@intel.com>,
"Helge Deller" <deller@gmx.de>,
"Javier Martinez Canillas" <javierm@redhat.com>,
"Daniel Vetter" <daniel@ffwll.ch>,
"Vineet Gupta" <vgupta@kernel.org>,
"Huacai Chen" <chenhuacai@kernel.org>,
"WANG Xuerui" <kernel@xen0n.name>,
"David S . Miller" <davem@davemloft.net>,
"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
"Sam Ravnborg" <sam@ravnborg.org>,
suijingfeng@loongson.cn, oe-kbuild-all@lists.linux.dev,
Linux-Arch <linux-arch@vger.kernel.org>,
linux-fbdev@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, linux-m68k@lists.linux-m68k.org,
loongarch@lists.linux.dev, sparclinux@vger.kernel.org,
linux-snps-arc@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h>
Date: Thu, 11 May 2023 15:40:28 +0200 [thread overview]
Message-ID: <d27e359c-1ea3-4d08-b124-e794fd372b28@app.fastmail.com> (raw)
In-Reply-To: <9c4be198444e9987c826c87b592e9dc6@artur-rojek.eu>
On Thu, May 11, 2023, at 15:22, Artur Rojek wrote:
> On 2023-05-11 14:35, Geert Uytterhoeven wrote:
>>
>> CC Artur, who's working on HP Jornada 680.
> Thanks for CC'ing me - I faced this exact issue while working on my
> (still not upstreamed) hd6446x PCMCIA controller driver. The PCMCIA
> subsystem uses `inb/outb`, which expect the `sh_io_port_base` to be set
> to something else than the default `-1`. At first I tried to set it to
> `0xa0000000`, so that all I/O goes through the fixed, non-cacheable P2
> area. That however broke some other driver code (I had no time to debug
> which one). Eventually I ended up taking a suggestion from a MIPS PCMCIA
> driver [1] and simply substract the broken `sh_io_port_base` address
> from `HD64461_IOBASE`, as the base for `socket.io_offset`. This way all
> the PCMCIA `inb/outb` accesses are absolute, no matter what the
> `sh_io_port_base` is set to. This of course is a very ugly solution and
> we should instead fix the root cause of this mess. I will have a better
> look at this patch set and the problem at hand at a later date.
>
> Cheers,
> Artur
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pcmcia/db1xxx_ss.c?h=v6.4-rc1#n527
I think the best fix would be to change all those drivers away
from using inb/outb to readb/writeb, except when they access the
actual PCMCIA I/O space behind the bridge.
On most of the modern architectures, inb(addr) now turns into
approximately readb(PCI_IOBASE + addr), with a bit of extra
logic to deal with endianess and barrier semantics.
PCI_IOBASE in turn tends to be a hardcoded virtual address
to which the physical I/O space window gets mapped during
early boot, though you can also #define it to sh_io_port_base
if you want to allocate the virtual address dynamically and
leave the existing logic unchanged.
Setting sh_io_port_base to zero however is a problem for any
driver that passes a small port number into it -- this then
turns into a user space pointer dereference, which is trivially
exploitable.
Arnd
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
WARNING: multiple messages have this Message-ID (diff)
From: "Arnd Bergmann" <arnd@arndb.de>
To: Artur Rojek <contact@artur-rojek.eu>,
Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-fbdev@vger.kernel.org, linux-ia64@vger.kernel.org,
dri-devel@lists.freedesktop.org,
"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
sparclinux@vger.kernel.org, WANG Xuerui <kernel@xen0n.name>,
Sam Ravnborg <sam@ravnborg.org>,
Linux-Arch <linux-arch@vger.kernel.org>,
kernel test robot <lkp@intel.com>, Helge Deller <deller@gmx.de>,
Huacai Chen <chenhuacai@kernel.org>,
Javier Martinez Canillas <javierm@redhat.com>,
Vineet Gupta <vgupta@kernel.org>,
linux-snps-arc@lists.infradead.org, suijingfeng@loongson.cn,
linux-m68k@lists.linux-m68k.org, loongarch@lists.linux.dev,
oe-kbuild-all@lists.linux.dev,
linux-arm-kernel@lists.infradead.org,
linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,
Thomas Zimmermann <tzimmermann@suse.de>,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h>
Date: Thu, 11 May 2023 13:40:28 +0000 [thread overview]
Message-ID: <d27e359c-1ea3-4d08-b124-e794fd372b28@app.fastmail.com> (raw)
In-Reply-To: <9c4be198444e9987c826c87b592e9dc6@artur-rojek.eu>
On Thu, May 11, 2023, at 15:22, Artur Rojek wrote:
> On 2023-05-11 14:35, Geert Uytterhoeven wrote:
>>
>> CC Artur, who's working on HP Jornada 680.
> Thanks for CC'ing me - I faced this exact issue while working on my
> (still not upstreamed) hd6446x PCMCIA controller driver. The PCMCIA
> subsystem uses `inb/outb`, which expect the `sh_io_port_base` to be set
> to something else than the default `-1`. At first I tried to set it to
> `0xa0000000`, so that all I/O goes through the fixed, non-cacheable P2
> area. That however broke some other driver code (I had no time to debug
> which one). Eventually I ended up taking a suggestion from a MIPS PCMCIA
> driver [1] and simply substract the broken `sh_io_port_base` address
> from `HD64461_IOBASE`, as the base for `socket.io_offset`. This way all
> the PCMCIA `inb/outb` accesses are absolute, no matter what the
> `sh_io_port_base` is set to. This of course is a very ugly solution and
> we should instead fix the root cause of this mess. I will have a better
> look at this patch set and the problem at hand at a later date.
>
> Cheers,
> Artur
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pcmcia/db1xxx_ss.c?h=v6.4-rc1#n527
I think the best fix would be to change all those drivers away
from using inb/outb to readb/writeb, except when they access the
actual PCMCIA I/O space behind the bridge.
On most of the modern architectures, inb(addr) now turns into
approximately readb(PCI_IOBASE + addr), with a bit of extra
logic to deal with endianess and barrier semantics.
PCI_IOBASE in turn tends to be a hardcoded virtual address
to which the physical I/O space window gets mapped during
early boot, though you can also #define it to sh_io_port_base
if you want to allocate the virtual address dynamically and
leave the existing logic unchanged.
Setting sh_io_port_base to zero however is a problem for any
driver that passes a small port number into it -- this then
turns into a user space pointer dereference, which is trivially
exploitable.
Arnd
next prev parent reply other threads:[~2023-05-11 13:41 UTC|newest]
Thread overview: 120+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-10 11:05 [PATCH v6 0/6] fbdev: Move framebuffer I/O helpers to <asm/fb.h> Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` [PATCH v6 1/6] fbdev/matrox: Remove trailing whitespaces Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 18:20 ` Sui Jingfeng
2023-05-10 18:20 ` Sui Jingfeng
2023-05-10 18:20 ` Sui Jingfeng
2023-05-11 7:55 ` Thomas Zimmermann
2023-05-11 7:55 ` Thomas Zimmermann
2023-05-11 7:55 ` Thomas Zimmermann
2023-05-11 7:55 ` Thomas Zimmermann
2023-05-11 9:24 ` Sui Jingfeng
2023-05-11 9:24 ` Sui Jingfeng
2023-05-11 9:24 ` Sui Jingfeng
2023-05-11 13:05 ` Helge Deller
2023-05-11 13:05 ` Helge Deller
2023-05-11 13:05 ` Helge Deller
2023-05-11 13:05 ` Helge Deller
2023-05-11 13:10 ` Geert Uytterhoeven
2023-05-11 13:10 ` Geert Uytterhoeven
2023-05-11 13:10 ` Geert Uytterhoeven
2023-05-11 13:10 ` Geert Uytterhoeven
2023-05-11 16:23 ` Helge Deller
2023-05-11 16:23 ` Helge Deller
2023-05-11 16:23 ` Helge Deller
2023-05-11 16:23 ` Helge Deller
2023-05-11 14:27 ` Thomas Zimmermann
2023-05-11 14:27 ` Thomas Zimmermann
2023-05-11 14:27 ` Thomas Zimmermann
2023-05-11 14:27 ` Thomas Zimmermann
2023-05-11 17:02 ` Helge Deller
2023-05-11 17:02 ` Helge Deller
2023-05-11 17:02 ` Helge Deller
2023-05-11 17:02 ` Helge Deller
2023-05-12 7:14 ` Thomas Zimmermann
2023-05-12 7:14 ` Thomas Zimmermann
2023-05-12 7:14 ` Thomas Zimmermann
2023-05-12 7:14 ` Thomas Zimmermann
2023-05-12 10:04 ` Finn Thain
2023-05-12 10:04 ` Finn Thain
2023-05-12 10:04 ` Finn Thain
2023-05-12 10:04 ` Finn Thain
2023-05-10 11:05 ` [PATCH v6 2/6] ipu-v3: Include <linux/io.h> Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` [PATCH v6 3/6] fbdev: Include <linux/io.h> in various drivers Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` [PATCH v6 4/6] fbdev: Include <linux/fb.h> instead of <asm/fb.h> Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h> Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 12:34 ` Geert Uytterhoeven
2023-05-10 12:34 ` Geert Uytterhoeven
2023-05-10 12:34 ` Geert Uytterhoeven
2023-05-10 12:34 ` Geert Uytterhoeven
2023-05-10 14:20 ` Thomas Zimmermann
2023-05-10 14:20 ` Thomas Zimmermann
2023-05-10 14:20 ` Thomas Zimmermann
2023-05-10 14:20 ` Thomas Zimmermann
2023-05-10 14:34 ` Geert Uytterhoeven
2023-05-10 14:34 ` Geert Uytterhoeven
2023-05-10 14:34 ` Geert Uytterhoeven
2023-05-10 14:34 ` Geert Uytterhoeven
2023-05-10 15:11 ` Thomas Zimmermann
2023-05-10 15:11 ` Thomas Zimmermann
2023-05-10 15:11 ` Thomas Zimmermann
2023-05-10 15:11 ` Thomas Zimmermann
2023-05-10 14:03 ` kernel test robot
2023-05-10 14:03 ` kernel test robot
2023-05-10 14:03 ` kernel test robot
2023-05-10 14:03 ` kernel test robot
2023-05-10 14:15 ` Arnd Bergmann
2023-05-10 14:15 ` Arnd Bergmann
2023-05-10 14:15 ` Arnd Bergmann
2023-05-10 14:15 ` Arnd Bergmann
2023-05-10 14:27 ` Thomas Zimmermann
2023-05-10 14:27 ` Thomas Zimmermann
2023-05-10 14:27 ` Thomas Zimmermann
2023-05-10 14:27 ` Thomas Zimmermann
2023-05-10 15:54 ` Arnd Bergmann
2023-05-10 15:54 ` Arnd Bergmann
2023-05-10 15:54 ` Arnd Bergmann
2023-05-10 15:54 ` Arnd Bergmann
2023-05-11 10:53 ` Thomas Zimmermann
2023-05-11 10:53 ` Thomas Zimmermann
2023-05-11 10:53 ` Thomas Zimmermann
2023-05-11 12:35 ` Geert Uytterhoeven
2023-05-11 12:35 ` Geert Uytterhoeven
2023-05-11 12:35 ` Geert Uytterhoeven
2023-05-11 12:35 ` Geert Uytterhoeven
2023-05-11 12:48 ` Arnd Bergmann
2023-05-11 12:48 ` Arnd Bergmann
2023-05-11 12:48 ` Arnd Bergmann
2023-05-11 12:48 ` Arnd Bergmann
2023-05-11 13:22 ` Artur Rojek
2023-05-11 13:22 ` Artur Rojek
2023-05-11 13:22 ` Artur Rojek
2023-05-11 13:22 ` Artur Rojek
2023-05-11 13:40 ` Arnd Bergmann [this message]
2023-05-11 13:40 ` Arnd Bergmann
2023-05-11 13:40 ` Arnd Bergmann
2023-05-11 13:40 ` Arnd Bergmann
2023-05-11 13:12 ` Thomas Zimmermann
2023-05-11 13:12 ` Thomas Zimmermann
2023-05-11 13:12 ` Thomas Zimmermann
2023-05-10 11:05 ` [PATCH v6 6/6] fbdev: Rename fb_mem*() helpers Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
2023-05-10 11:05 ` Thomas Zimmermann
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