[PATCH] platform/x86: dell-wmi-sysman: Fix instance ID bounds

The get_instance_id() macro walks the per-type attribute array with
'i <= instances_count'.  Each array is allocated with exactly
instances_count entries, so the valid range is [0, instances_count)
and the last iteration reads one element past the end.  On a name miss
that out-of-bounds attribute_name is handed to strcmp(), which reads on
until it finds a NUL byte.

Every kobject in these ksets is built from an entry that was populated,
so a miss does not look reachable from sysfs today.  The bound is wrong
either way and the read is out of bounds.

The matching macro in hp-bioscfg carried the same off-by-one and was
corrected by commit 25150715e0b0 ("platform/x86: hp-bioscfg: Fix kernel
panic in GET_INSTANCE_ID macro").  That macro takes a kobject pointer
out of the out-of-bounds element and dereferences it, so it could fault.
This one reads a char array.

Use '<' to match the allocation.

Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <[email protected]>
---
 drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
index 3bddedad5eba..eb48ced55823 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/dell-wmi-sysman.h
@@ -107,7 +107,7 @@ enum {
 static int get_##type##_instance_id(struct kobject *kobj)			\
 {										\
 	int i;									\
-	for (i = 0; i <= wmi_priv.type##_instances_count; i++) {		\
+	for (i = 0; i < wmi_priv.type##_instances_count; i++) {			\
 		if (!(strcmp(kobj->name, wmi_priv.type##_data[i].attribute_name)))\
 			return i;						\
 	}									\
-- 
2.43.0