[PATCH] acpica: Fix segfault when disassembling AML (LP: #1050475)

[Keng-Yu Lin]

On Fri, Sep 14, 2012 at 12:04 AM, Colin King <colin.king at canonical.com> wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> Running fwts against a collection of test tables I found a segfault
> in source/components/disassembler/dmopcode.c:334, due to Tag being
> null. This patch is a fix from Robert Moore at Intel which will land
> in the September release of ACPICA/iASL.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  src/acpica/source/common/dmrestag.c                  |    5 +++++
>  src/acpica/source/components/disassembler/dmopcode.c |    4 ++++
>  2 files changed, 9 insertions(+)
>
> diff --git a/src/acpica/source/common/dmrestag.c b/src/acpica/source/common/dmrestag.c
> index 9afaad3..3097f15 100644
> --- a/src/acpica/source/common/dmrestag.c
> +++ b/src/acpica/source/common/dmrestag.c
> @@ -541,6 +541,11 @@ AcpiDmCheckResourceReference (
>      /* Get the Index term, must be an integer constant to convert */
>
>      IndexOp = BufferNameOp->Common.Next;
> +
> +    /* Major cheat: The Node field is also used for the Tag ptr. Clear it now */
> +
> +    IndexOp->Common.Node = NULL;
> +
>      OpInfo = AcpiPsGetOpcodeInfo (IndexOp->Common.AmlOpcode);
>      if (OpInfo->ObjectType != ACPI_TYPE_INTEGER)
>      {
> diff --git a/src/acpica/source/components/disassembler/dmopcode.c b/src/acpica/source/components/disassembler/dmopcode.c
> index 252b1b8..c6fa387 100644
> --- a/src/acpica/source/components/disassembler/dmopcode.c
> +++ b/src/acpica/source/components/disassembler/dmopcode.c
> @@ -326,6 +326,10 @@ AcpiDmFieldPredefinedDescription (
>      /* Major cheat: We previously put the Tag ptr in the Node field */
>
>      Tag = ACPI_CAST_PTR (char, IndexOp->Common.Node);
> +    if (!Tag)
> +    {
> +        return;
> +    }
>
>      /* Match the name in the info table */
>
> --
> 1.7.10.4
>

Acked-by: Keng-Yu Lin <kengyu at canonical.com>