drivers/platform/x86: Eliminate a NULL pointer dereference
Give different error messages if device_enum is NULL or if its type field
has the wrong value.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@
if ((E == NULL && ...) || ...)
{
... when != if (...) S1 else S2
when != E = E1
* E->f
... when any
return ...;
}
else S3
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 1387c5f..a47fd4e 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1196,9 +1196,13 @@
}
device_enum = (union acpi_object *) buffer.pointer;
- if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
- printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
- device_enum->type);
+ if (!device_enum) {
+ pr_err("Invalid SN06 return object\n");
+ goto out_no_enum;
+ }
+ if (device_enum->type != ACPI_TYPE_BUFFER) {
+ pr_err("Invalid SN06 return object type 0x%.2x\n",
+ device_enum->type);
goto out_no_enum;
}