Date: Sun, 16 Sep 2001 22:57:30 +0200 (CEST) From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: FreeBSD-gnats-submit@freebsd.org Subject: kern/30617: [PATCH] ACPI bug: don't dereference a pointer you have set to NULL Message-ID: <200109162057.f8GKvUN99682@critter.freebsd.dk>
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>Number: 30617
>Category: kern
>Synopsis: [PATCH] ACPI bug: don't dereference a pointer you have set to NULL
>Confidential: no
>Severity: critical
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Sep 16 14:00:01 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator: Poul-Henning Kamp
>Release: FreeBSD 5.0-CURRENT i386
>Organization:
International Keep It Simple Stupid! brotherhood
>Environment:
System: FreeBSD critter.freebsd.dk 5.0-CURRENT FreeBSD 5.0-CURRENT #1: Wed Aug 8 13:10:20 CEST 2001 root@critter.freebsd.dk:/freebsd/src/sys/i386/compile/CRITTER i386
>Description:
In AcpiExDyadic1() a DEBUG statement tried to dereference the pointer
"Operand[0]" which has explictly been set to NULL earlier in the same
function. This panics the kernel.
>How-To-Repeat:
Pull the powerplug on an Asus M1300 machine with bios 1.05
>Fix:
This patch is a workaround, I don't know enough about the ACPI code to judge if
the setting of "Operand[0] = NULL" is kosher or bogus, so I have simply added
an if() to avoid dereferencing the NULL pointer.
Index: exdyadic.c
===================================================================
RCS file: /home/ncvs/src/sys/contrib/dev/acpica/exdyadic.c,v
retrieving revision 1.1.1.9
diff -u -r1.1.1.9 exdyadic.c
--- exdyadic.c 7 Sep 2001 01:22:24 -0000 1.1.1.9
+++ exdyadic.c 16 Sep 2001 20:41:41 -0000
@@ -375,8 +375,11 @@
break;
default:
- ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unexpected notify object type %X\n",
- Operand[0]->Common.Type));
+ if (Operand[0] == NULL)
+ ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unexpected notify object type (details at 11...)\n"));
+ else
+ ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unexpected notify object type %X\n",
+ Operand[0]->Common.Type));
Status = AE_AML_OPERAND_TYPE;
break;
>Release-Note:
>Audit-Trail:
>Unformatted:
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