ASoC: dapm: fix bounds checker error in dapm_widget_list_create

The widgets array in the snd_soc_dapm_widget_list has a __counted_by
attribute attached to it, which points to the num_widgets variable. This
attribute is used in bounds checking, and if it is not set before the
array is filled, then the bounds sanitizer will issue a warning or a
kernel panic if CONFIG_UBSAN_TRAP is set.

This patch sets the size of the widgets list calculated with
list_for_each as the initial value for num_widgets as it is used for
allocating memory for the array. It is updated with the actual number of
added elements after the array is filled.

Signed-off-by: Aleksei Vetrov <vvvvvv@google.com>
Fixes: 80e698e2df5b ("ASoC: soc-dapm: Annotate struct snd_soc_dapm_widget_list with __counted_by")
Link: https://patch.msgid.link/20241028-soc-dapm-bounds-checker-fix-v1-1-262b0394e89e@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index c34934c31ffec3970b34b24dcaa0826dfb7d8e86..99521c784a9b16a232a558029a2f3e88bd8ebfb1 100644 (file)
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1147,6 +1147,8 @@ static int dapm_widget_list_create(struct snd_soc_dapm_widget_list **list,
        if (*list == NULL)
                return -ENOMEM;
 
+       (*list)->num_widgets = size;
+
        list_for_each_entry(w, widgets, work_list)
                (*list)->widgets[i++] = w;