diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index bdc1bf7bf22d..3c45c1c15f7e 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -561,7 +561,7 @@ static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg)
 {
 	struct stm_device *stm = stmf->stm;
 	struct stp_policy_id *id;
-	int ret = -EINVAL;
+	int ret = -EINVAL, wlimit = 1;
 	u32 size;
 
 	if (stmf->output.nr_chans)
@@ -589,8 +589,10 @@ static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg)
 	if (id->__reserved_0 || id->__reserved_1)
 		goto err_free;
 
-	if (id->width < 1 ||
-	    id->width > PAGE_SIZE / stm->data->sw_mmiosz)
+	if (stm->data->sw_mmiosz)
+		wlimit = PAGE_SIZE / stm->data->sw_mmiosz;
+
+	if (id->width < 1 || id->width > wlimit)
 		goto err_free;
 
 	ret = stm_file_assign(stmf, id->id, id->width);