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

[Alex Hung]

On 09/14/2012 12:04 AM, Colin King 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 */
>
>
Acked-by: Alex Hung <alex.hung at canonical.com>