From: Jason Liu <[email protected]>
The driver install one hook to handle the external abort, but issue
is that if the abort introduced from user space code, the following
code unsigned long instr = *(unsigned long *)pc; which will created
another data-abort(page domain fault) if CONFIG_CPU_SW_DOMAIN_PAN.
The patch does not intent to use copy_from_user and then do the hack
due to the security consideration. In fact, we can just return and
report the external abort to user-space.
Signed-off-by: Jason Liu <[email protected]>
Reviewed-by: Richard Zhu <[email protected]>
Signed-off-by: Francesco Dolcini <[email protected]>
---
We have this patch from NXP downstream kernel [1] in our kernel branch [2]
since a long time, to me it would make sense to upstream it. Any concern?
[1] https://source.codeaurora.org/external/imxsupport/linux-imx/commit/?id=62dfb2fb953463dd1b6710567c9e174672a98f24
[2] https://git.toradex.com/cgit/linux-toradex.git/commit/?id=2b42547cf659f979be2defdff6a99f921b33d0f1
---
drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 6974bd5aa116..6b178a29e253 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -27,6 +27,7 @@
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
+#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/reset.h>
#include <linux/phy/phy.h>
@@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
unsigned int fsr, struct pt_regs *regs)
{
unsigned long pc = instruction_pointer(regs);
- unsigned long instr = *(unsigned long *)pc;
- int reg = (instr >> 12) & 15;
+ unsigned long instr;
+ int reg;
+
+ /* if the abort from user-space, just return and report it */
+ if (user_mode(regs))
+ return 1;
+
+ instr = *(unsigned long *)pc;
+ reg = (instr >> 12) & 15;
/*
* If the instruction being executed was a read,
--
2.25.1
Am Freitag, dem 28.01.2022 um 09:29 +0100 schrieb Francesco Dolcini:
> From: Jason Liu <[email protected]>
>
> The driver install one hook to handle the external abort, but issue
> is that if the abort introduced from user space code, the following
> code unsigned long instr = *(unsigned long *)pc; which will created
> another data-abort(page domain fault) if CONFIG_CPU_SW_DOMAIN_PAN.
>
> The patch does not intent to use copy_from_user and then do the hack
> due to the security consideration. In fact, we can just return and
> report the external abort to user-space.
>
I'm not sure how userspace would be able to trigger this abort. Maybe
invalid access to a device cfg space via sysfs?
However the patch seems to do the right thing in that case.
Acked-by: Lucas Stach <[email protected]>
> Signed-off-by: Jason Liu <[email protected]>
> Reviewed-by: Richard Zhu <[email protected]>
> Signed-off-by: Francesco Dolcini <[email protected]>
> ---
> We have this patch from NXP downstream kernel [1] in our kernel branch [2]
> since a long time, to me it would make sense to upstream it. Any concern?
>
> [1] https://source.codeaurora.org/external/imxsupport/linux-imx/commit/?id=62dfb2fb953463dd1b6710567c9e174672a98f24
> [2] https://git.toradex.com/cgit/linux-toradex.git/commit/?id=2b42547cf659f979be2defdff6a99f921b33d0f1
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 6974bd5aa116..6b178a29e253 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -27,6 +27,7 @@
> #include <linux/resource.h>
> #include <linux/signal.h>
> #include <linux/types.h>
> +#include <linux/uaccess.h>
> #include <linux/interrupt.h>
> #include <linux/reset.h>
> #include <linux/phy/phy.h>
> @@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
> unsigned int fsr, struct pt_regs *regs)
> {
> unsigned long pc = instruction_pointer(regs);
> - unsigned long instr = *(unsigned long *)pc;
> - int reg = (instr >> 12) & 15;
> + unsigned long instr;
> + int reg;
> +
> + /* if the abort from user-space, just return and report it */
> + if (user_mode(regs))
> + return 1;
> +
> + instr = *(unsigned long *)pc;
> + reg = (instr >> 12) & 15;
>
> /*
> * If the instruction being executed was a read,
> -----Original Message-----
> From: Francesco Dolcini <[email protected]>
> Sent: 2022??1??28?? 16:29
> To: Hongxing Zhu <[email protected]>; Lucas Stach
> <[email protected]>; Lorenzo Pieralisi <[email protected]>; Rob
> Herring <[email protected]>; Krzysztof Wilczy??ski <[email protected]>; Sascha
> Hauer <[email protected]>; Pengutronix Kernel Team
> <[email protected]>; Fabio Estevam <[email protected]>;
> dl-linux-imx <[email protected]>; Jason Liu <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; Bjorn Helgaas <[email protected]>; Shawn
> Guo <[email protected]>; Francesco Dolcini
> <[email protected]>
> Subject: [RFC PATCH] PCI: imx6: Handle the abort from user-space
>
> From: Jason Liu <[email protected]>
>
> The driver install one hook to handle the external abort, but issue is that if the
> abort introduced from user space code, the following code unsigned long instr
> = *(unsigned long *)pc; which will created another data-abort(page domain
> fault) if CONFIG_CPU_SW_DOMAIN_PAN.
>
> The patch does not intent to use copy_from_user and then do the hack due to
> the security consideration. In fact, we can just return and report the external
> abort to user-space.
>
> Signed-off-by: Jason Liu <[email protected]>
> Reviewed-by: Richard Zhu <[email protected]>
> Signed-off-by: Francesco Dolcini <[email protected]>
> ---
> We have this patch from NXP downstream kernel [1] in our kernel branch [2]
> since a long time, to me it would make sense to upstream it. Any concern?
>
> [1]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.
> codeaurora.org%2Fexternal%2Fimxsupport%2Flinux-imx%2Fcommit%2F%3Fid
> %3D62dfb2fb953463dd1b6710567c9e174672a98f24&data=04%7C01%7
> Chongxing.zhu%40nxp.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C68
> 6ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637789553659549198%7
> CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT
> iI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Mwhx8DFF7EDJdpqTsHT
> %2BBAGzhQadDOqcgJnVjeoi1yk%3D&reserved=0
> [2]
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.tora
> dex.com%2Fcgit%2Flinux-toradex.git%2Fcommit%2F%3Fid%3D2b42547cf659f
> 979be2defdff6a99f921b33d0f1&data=04%7C01%7Chongxing.zhu%40nx
> p.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C686ea1d3bc2b4c6fa92c
> d99c5c301635%7C0%7C0%7C637789553659549198%7CUnknown%7CTWFp
> bGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
> 6Mn0%3D%7C3000&sdata=QEW1frh8WacCzniWo4ng1cy3Z1UZ9uMRFw
> GBKuIh7zE%3D&reserved=0
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> b/drivers/pci/controller/dwc/pci-imx6.c
> index 6974bd5aa116..6b178a29e253 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -27,6 +27,7 @@
> #include <linux/resource.h>
> #include <linux/signal.h>
> #include <linux/types.h>
> +#include <linux/uaccess.h>
[Richard Zhu] Thanks for your kindly help.
This header include is not required actually, please remove it.
Best Regards
Richard
> #include <linux/interrupt.h>
> #include <linux/reset.h>
> #include <linux/phy/phy.h>
> @@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long
> addr,
> unsigned int fsr, struct pt_regs *regs) {
> unsigned long pc = instruction_pointer(regs);
> - unsigned long instr = *(unsigned long *)pc;
> - int reg = (instr >> 12) & 15;
> + unsigned long instr;
> + int reg;
> +
> + /* if the abort from user-space, just return and report it */
> + if (user_mode(regs))
> + return 1;
> +
> + instr = *(unsigned long *)pc;
> + reg = (instr >> 12) & 15;
>
> /*
> * If the instruction being executed was a read,
> --
> 2.25.1
Am Freitag, 28. Januar 2022, 10:25:11 CET schrieb Hongxing Zhu:
> > -----Original Message-----
> > From: Francesco Dolcini <[email protected]>
> > Sent: 2022年1月28日 16:29
> > To: Hongxing Zhu <[email protected]>; Lucas Stach
> > <[email protected]>; Lorenzo Pieralisi <[email protected]>;
> > Rob
Herring <[email protected]>; Krzysztof Wilczyński <[email protected]>;
> > Sascha Hauer <[email protected]>; Pengutronix Kernel Team
> > <[email protected]>; Fabio Estevam <[email protected]>;
> > dl-linux-imx <[email protected]>; Jason Liu <[email protected]>
> > Cc: [email protected]; [email protected];
> > [email protected]; Bjorn Helgaas <[email protected]>; Shawn
> > Guo <[email protected]>; Francesco Dolcini
> > <[email protected]>
> > Subject: [RFC PATCH] PCI: imx6: Handle the abort from user-space
> >
> > From: Jason Liu <[email protected]>
> >
> > The driver install one hook to handle the external abort, but issue is
> > that if the
abort introduced from user space code, the following code
> > unsigned long instr = *(unsigned long *)pc; which will created another
> > data-abort(page domain fault) if CONFIG_CPU_SW_DOMAIN_PAN.
> >
> > The patch does not intent to use copy_from_user and then do the hack due
> > to
the security consideration. In fact, we can just return and report
> > the external abort to user-space.
> >
> > Signed-off-by: Jason Liu <[email protected]>
> > Reviewed-by: Richard Zhu <[email protected]>
> > Signed-off-by: Francesco Dolcini <[email protected]>
> > ---
> > We have this patch from NXP downstream kernel [1] in our kernel branch
> > [2]
> > since a long time, to me it would make sense to upstream it. Any concern?
> >
> > [1]
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource.
> > codeaurora.org%2Fexternal%2Fimxsupport%2Flinux-imx%2Fcommit%2F%3Fid
> > %3D62dfb2fb953463dd1b6710567c9e174672a98f24&data=04%7C01%7
> > Chongxing.zhu%40nxp.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C68
> > 6ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637789553659549198%7
> > CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT
> > iI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Mwhx8DFF7EDJdpqTsHT
> > %2BBAGzhQadDOqcgJnVjeoi1yk%3D&reserved=0
> > [2]
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.tora
> >
> > dex.com%2Fcgit%2Flinux-toradex.git%2Fcommit%2F%3Fid%3D2b42547cf659f
> > 979be2defdff6a99f921b33d0f1&data=04%7C01%7Chongxing.zhu%40nx
> > p.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C686ea1d3bc2b4c6fa92c
> > d99c5c301635%7C0%7C0%7C637789553659549198%7CUnknown%7CTWFp
> > bGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
> > 6Mn0%3D%7C3000&sdata=QEW1frh8WacCzniWo4ng1cy3Z1UZ9uMRFw
> > GBKuIh7zE%3D&reserved=0
> > ---
> >
> > drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 6974bd5aa116..6b178a29e253 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -27,6 +27,7 @@
> >
> > #include <linux/resource.h>
> > #include <linux/signal.h>
> > #include <linux/types.h>
> >
> > +#include <linux/uaccess.h>
>
>
> [Richard Zhu] Thanks for your kindly help.
> This header include is not required actually, please remove it.
It should be <linux/ptrace.h> instead, for using user_mode().
Best regards,
Alexander
> > #include <linux/interrupt.h>
> > #include <linux/reset.h>
> > #include <linux/phy/phy.h>
> >
> > @@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long
> > addr,
> >
> > unsigned int fsr, struct pt_regs *regs) {
> >
> > unsigned long pc = instruction_pointer(regs);
> >
> > - unsigned long instr = *(unsigned long *)pc;
> > - int reg = (instr >> 12) & 15;
> > + unsigned long instr;
> > + int reg;
> > +
> > + /* if the abort from user-space, just return and report it */
> > + if (user_mode(regs))
> > + return 1;
> > +
> > + instr = *(unsigned long *)pc;
> > + reg = (instr >> 12) & 15;
> >
> >
> > /*
> >
> > * If the instruction being executed was a read,
> >
> > --
> > 2.25.1
>
>