2020-08-04 12:32:32

by Geert Uytterhoeven

[permalink] [raw]
Subject: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

The conversion to modern host bridge probing made the driver allocate
its private data using devm_pci_alloc_host_bridge(), but forgot to
remove the old allocation. Hence part of the driver initialization is
done using the new instance, while another part is done using the old
instance, leading to a crash due to uninitialized bridge DMA ranges:

Unable to handle kernel NULL pointer dereference at virtual address 00000008
pgd = (ptrval)
[00000008] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
PC is at rcar_pci_probe+0x154/0x340
LR is at _raw_spin_unlock_irqrestore+0x18/0x20

Fix this by dropping the old allocation.

Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
Signed-off-by: Geert Uytterhoeven <[email protected]>
---
drivers/pci/controller/pci-rcar-gen2.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
index 046965d284a6d54e..c9530038ca9a53fc 100644
--- a/drivers/pci/controller/pci-rcar-gen2.c
+++ b/drivers/pci/controller/pci-rcar-gen2.c
@@ -302,10 +302,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
if (mem_res->start & 0xFFFF)
return -EINVAL;

- priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
-
priv->mem_res = *mem_res;
priv->cfg_res = cfg_res;

--
2.17.1


2020-08-04 15:18:16

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

On Tue, Aug 4, 2020 at 6:04 AM Geert Uytterhoeven
<[email protected]> wrote:
>
> The conversion to modern host bridge probing made the driver allocate
> its private data using devm_pci_alloc_host_bridge(), but forgot to
> remove the old allocation. Hence part of the driver initialization is
> done using the new instance, while another part is done using the old
> instance, leading to a crash due to uninitialized bridge DMA ranges:
>
> Unable to handle kernel NULL pointer dereference at virtual address 00000008
> pgd = (ptrval)
> [00000008] *pgd=00000000
> Internal error: Oops: 5 [#1] SMP ARM
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
> Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> PC is at rcar_pci_probe+0x154/0x340
> LR is at _raw_spin_unlock_irqrestore+0x18/0x20
>
> Fix this by dropping the old allocation.
>
> Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> drivers/pci/controller/pci-rcar-gen2.c | 4 ----
> 1 file changed, 4 deletions(-)

Acked-by: Rob Herring <[email protected]>

2020-08-04 16:14:14

by Lorenzo Pieralisi

[permalink] [raw]
Subject: Re: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

On Tue, Aug 04, 2020 at 02:04:30PM +0200, Geert Uytterhoeven wrote:
> The conversion to modern host bridge probing made the driver allocate
> its private data using devm_pci_alloc_host_bridge(), but forgot to
> remove the old allocation. Hence part of the driver initialization is
> done using the new instance, while another part is done using the old
> instance, leading to a crash due to uninitialized bridge DMA ranges:
>
> Unable to handle kernel NULL pointer dereference at virtual address 00000008
> pgd = (ptrval)
> [00000008] *pgd=00000000
> Internal error: Oops: 5 [#1] SMP ARM
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
> Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> PC is at rcar_pci_probe+0x154/0x340
> LR is at _raw_spin_unlock_irqrestore+0x18/0x20
>
> Fix this by dropping the old allocation.
>
> Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> drivers/pci/controller/pci-rcar-gen2.c | 4 ----
> 1 file changed, 4 deletions(-)

Squashed in the initial commit, pushed out on pci/misc.

Thanks,
Lorenzo

> diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
> index 046965d284a6d54e..c9530038ca9a53fc 100644
> --- a/drivers/pci/controller/pci-rcar-gen2.c
> +++ b/drivers/pci/controller/pci-rcar-gen2.c
> @@ -302,10 +302,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
> if (mem_res->start & 0xFFFF)
> return -EINVAL;
>
> - priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
> - if (!priv)
> - return -ENOMEM;
> -
> priv->mem_res = *mem_res;
> priv->cfg_res = cfg_res;
>
> --
> 2.17.1
>

2020-08-04 16:27:43

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

On Tue, Aug 04, 2020 at 05:13:25PM +0100, Lorenzo Pieralisi wrote:
> On Tue, Aug 04, 2020 at 02:04:30PM +0200, Geert Uytterhoeven wrote:
> > The conversion to modern host bridge probing made the driver allocate
> > its private data using devm_pci_alloc_host_bridge(), but forgot to
> > remove the old allocation. Hence part of the driver initialization is
> > done using the new instance, while another part is done using the old
> > instance, leading to a crash due to uninitialized bridge DMA ranges:
> >
> > Unable to handle kernel NULL pointer dereference at virtual address 00000008
> > pgd = (ptrval)
> > [00000008] *pgd=00000000
> > Internal error: Oops: 5 [#1] SMP ARM
> > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
> > Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> > PC is at rcar_pci_probe+0x154/0x340
> > LR is at _raw_spin_unlock_irqrestore+0x18/0x20
> >
> > Fix this by dropping the old allocation.
> >
> > Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
> > Signed-off-by: Geert Uytterhoeven <[email protected]>
> > ---
> > drivers/pci/controller/pci-rcar-gen2.c | 4 ----
> > 1 file changed, 4 deletions(-)
>
> Squashed in the initial commit, pushed out on pci/misc.

I updated my 'next' branch with this.

Rob, are there any similar issues in other drivers that we should fix
before asking Linus to pull this?

> > diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
> > index 046965d284a6d54e..c9530038ca9a53fc 100644
> > --- a/drivers/pci/controller/pci-rcar-gen2.c
> > +++ b/drivers/pci/controller/pci-rcar-gen2.c
> > @@ -302,10 +302,6 @@ static int rcar_pci_probe(struct platform_device *pdev)
> > if (mem_res->start & 0xFFFF)
> > return -EINVAL;
> >
> > - priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
> > - if (!priv)
> > - return -ENOMEM;
> > -
> > priv->mem_res = *mem_res;
> > priv->cfg_res = cfg_res;
> >
> > --
> > 2.17.1
> >

2020-08-04 16:50:22

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

On Tue, Aug 4, 2020 at 10:22 AM Bjorn Helgaas <[email protected]> wrote:
>
> On Tue, Aug 04, 2020 at 05:13:25PM +0100, Lorenzo Pieralisi wrote:
> > On Tue, Aug 04, 2020 at 02:04:30PM +0200, Geert Uytterhoeven wrote:
> > > The conversion to modern host bridge probing made the driver allocate
> > > its private data using devm_pci_alloc_host_bridge(), but forgot to
> > > remove the old allocation. Hence part of the driver initialization is
> > > done using the new instance, while another part is done using the old
> > > instance, leading to a crash due to uninitialized bridge DMA ranges:
> > >
> > > Unable to handle kernel NULL pointer dereference at virtual address 00000008
> > > pgd = (ptrval)
> > > [00000008] *pgd=00000000
> > > Internal error: Oops: 5 [#1] SMP ARM
> > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
> > > Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> > > PC is at rcar_pci_probe+0x154/0x340
> > > LR is at _raw_spin_unlock_irqrestore+0x18/0x20
> > >
> > > Fix this by dropping the old allocation.
> > >
> > > Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
> > > Signed-off-by: Geert Uytterhoeven <[email protected]>
> > > ---
> > > drivers/pci/controller/pci-rcar-gen2.c | 4 ----
> > > 1 file changed, 4 deletions(-)
> >
> > Squashed in the initial commit, pushed out on pci/misc.
>
> I updated my 'next' branch with this.
>
> Rob, are there any similar issues in other drivers that we should fix
> before asking Linus to pull this?

I'd expect only different issues. :)

This commit is unique as it was using the old arm32 PCI functions and
the most complicated change of the lot.

Rob