[PATCH] xfree86: bail on misformed acpi strings (#73227)

[Peter Hutterer]

From: Ted Felix <ted at tedfelix.com>

If acpid sends a string in a format that we can't parse, bail out instead of
potentially dereferencing a NULL-pointer.

X.Org Bug 73227 <http://bugs.freedesktop.org/show_bug.cgi?id=73227>

Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
Ted, can I have your Signed-off-by for this patch?

 hw/xfree86/os-support/linux/lnx_acpi.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/hw/xfree86/os-support/linux/lnx_acpi.c b/hw/xfree86/os-support/linux/lnx_acpi.c
index d98efa2..dcaa19e 100644
--- a/hw/xfree86/os-support/linux/lnx_acpi.c
+++ b/hw/xfree86/os-support/linux/lnx_acpi.c
@@ -82,18 +82,21 @@ lnxACPIGetEventFromOs(int fd, pmEvent * events, int num)
 
         video = strtok(ev, " ");
 
-        GFX = strtok(NULL, " ");
+        if (!(GFX = strtok(NULL, " ")))
+            return 0;
 #if 0
         ErrorF("GFX: %s\n", GFX);
 #endif
 
-        notify = strtok(NULL, " ");
+        if (!(notify = strtok(NULL, " ")))
+            return 0;
         notify_l = strtoul(notify, NULL, 16);
 #if 0
         ErrorF("notify: 0x%lx\n", notify_l);
 #endif
 
-        data = strtok(NULL, " ");
+        if (!(data = strtok(NULL, " ")))
+            return 0;
         data_l = strtoul(data, NULL, 16);
 #if 0
         ErrorF("data: 0x%lx\n", data_l);
-- 
1.8.1