[PATCH] arm/efi: Fix null pointer dereference

Luca Fancellu posted 1 patch 1 week, 4 days ago
xen/arch/arm/efi/efi-boot.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

[PATCH] arm/efi: Fix null pointer dereference

Posted by Luca Fancellu 1 week, 4 days ago
Fix for commit 60649d443dc395243e74d2b3e05594ac0c43cfe3
that introduces a null pointer dereference when the
fdt_node_offset_by_compatible is called with "fdt"
argument null.

Reported-by: Julien Grall <julien@xen.org>
Fixes: 60649d443d ("arm/efi: Introduce xen,uefi-cfg-load DT property")
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
 xen/arch/arm/efi/efi-boot.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index a3e46453d4..e63dafac26 100644
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -593,7 +593,8 @@ static bool __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
     dtbfile.ptr = fdt;
     dtbfile.need_to_free = false; /* Config table memory can't be freed. */
 
-    if ( fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0 )
+    if ( fdt &&
+         (fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0) )
     {
         /* Locate chosen node */
         int node = fdt_subnode_offset(fdt, 0, "chosen");
-- 
2.17.1


Re: [PATCH] arm/efi: Fix null pointer dereference

Posted by Bertrand Marquis 1 week, 4 days ago
Hi Luca,

> On 11 Oct 2021, at 08:56, Luca Fancellu <Luca.Fancellu@arm.com> wrote:
> 
> Fix for commit 60649d443dc395243e74d2b3e05594ac0c43cfe3
> that introduces a null pointer dereference when the
> fdt_node_offset_by_compatible is called with "fdt"
> argument null.
> 
> Reported-by: Julien Grall <julien@xen.org>
> Fixes: 60649d443d ("arm/efi: Introduce xen,uefi-cfg-load DT property")
> Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Cheers
Bertrand


> ---
> xen/arch/arm/efi/efi-boot.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
> index a3e46453d4..e63dafac26 100644
> --- a/xen/arch/arm/efi/efi-boot.h
> +++ b/xen/arch/arm/efi/efi-boot.h
> @@ -593,7 +593,8 @@ static bool __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
>     dtbfile.ptr = fdt;
>     dtbfile.need_to_free = false; /* Config table memory can't be freed. */
> 
> -    if ( fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0 )
> +    if ( fdt &&
> +         (fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0) )
>     {
>         /* Locate chosen node */
>         int node = fdt_subnode_offset(fdt, 0, "chosen");
> -- 
> 2.17.1
> 


Re: [PATCH] arm/efi: Fix null pointer dereference

Posted by Stefano Stabellini 1 week, 3 days ago
On Mon, 11 Oct 2021, Bertrand Marquis wrote:
> Hi Luca,
> 
> > On 11 Oct 2021, at 08:56, Luca Fancellu <Luca.Fancellu@arm.com> wrote:
> > 
> > Fix for commit 60649d443dc395243e74d2b3e05594ac0c43cfe3
> > that introduces a null pointer dereference when the
> > fdt_node_offset_by_compatible is called with "fdt"
> > argument null.
> > 
> > Reported-by: Julien Grall <julien@xen.org>
> > Fixes: 60649d443d ("arm/efi: Introduce xen,uefi-cfg-load DT property")
> > Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
> Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> > ---
> > xen/arch/arm/efi/efi-boot.h | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
> > index a3e46453d4..e63dafac26 100644
> > --- a/xen/arch/arm/efi/efi-boot.h
> > +++ b/xen/arch/arm/efi/efi-boot.h
> > @@ -593,7 +593,8 @@ static bool __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
> >     dtbfile.ptr = fdt;
> >     dtbfile.need_to_free = false; /* Config table memory can't be freed. */
> > 
> > -    if ( fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0 )
> > +    if ( fdt &&
> > +         (fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") > 0) )
> >     {
> >         /* Locate chosen node */
> >         int node = fdt_subnode_offset(fdt, 0, "chosen");
> > -- 
> > 2.17.1
> > 
>