The bug is here:
*dai_name = dai->driver->name;
For for_each_component_dais, just like list_for_each_entry,
the list iterator 'dai' will point to a bogus position
containing HEAD if the list is empty or no element is found.
This case must be checked before any use of the iterator,
otherwise it will lead to a invalid memory access.
To fix the bug, use a new variable 'iter' as the list iterator,
while use the original variable 'dai' as a dedicated pointer
to point to the found element.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 58bf4179000a3 ("ASoC: soc-core: remove dai_drv from snd_soc_component")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
---
sound/soc/soc-core.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 434e61b46983..064fc0347868 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -3238,7 +3238,7 @@ int snd_soc_get_dai_name(const struct of_phandle_args *args,
ret = snd_soc_component_of_xlate_dai_name(pos, args, dai_name);
if (ret == -ENOTSUPP) {
- struct snd_soc_dai *dai;
+ struct snd_soc_dai *dai = NULL, *iter;
int id = -1;
switch (args->args_count) {
@@ -3261,12 +3261,19 @@ int snd_soc_get_dai_name(const struct of_phandle_args *args,
ret = 0;
/* find target DAI */
- for_each_component_dais(pos, dai) {
- if (id == 0)
+ for_each_component_dais(pos, iter) {
+ if (id == 0) {
+ dai = iter;
break;
+ }
id--;
}
+ if (!dai) {
+ ret = -EINVAL;
+ continue;
+ }
+
*dai_name = dai->driver->name;
if (!*dai_name)
*dai_name = pos->name;
--
2.17.1
