[PATCH] ASoC: sdw_utils: fix double put_device() on aggregated amps

From: Jack Yu <[email protected]>

In aggregation mode with two identical amplifiers,
a stress test that repeatedly triggers card unbind/rebind
can hit a NULL pointer dereference during the exit path.
ctx->amp_dev1 / ctx->amp_dev2 are single shared resources,
so the release must be safe against being called more than once.
Clear each pointer after put_device() so a second invocation
becomes a no-op, this could address NULL pointer dereference issue.

Signed-off-by: Jack Yu <[email protected]>
---
 sound/soc/sdw_utils/soc_sdw_rt_amp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/sdw_utils/soc_sdw_rt_amp.c b/sound/soc/sdw_utils/soc_sdw_rt_amp.c
index 4e9b08cb653d..81d2cbac0ea3 100644
--- a/sound/soc/sdw_utils/soc_sdw_rt_amp.c
+++ b/sound/soc/sdw_utils/soc_sdw_rt_amp.c
@@ -252,11 +252,13 @@ int asoc_sdw_rt_amp_exit(struct snd_soc_card *card, struct snd_soc_dai_link *dai
 	if (ctx->amp_dev1) {
 		device_remove_software_node(ctx->amp_dev1);
 		put_device(ctx->amp_dev1);
+		ctx->amp_dev1 = NULL;
 	}
 
 	if (ctx->amp_dev2) {
 		device_remove_software_node(ctx->amp_dev2);
 		put_device(ctx->amp_dev2);
+		ctx->amp_dev2 = NULL;
 	}
 
 	return 0;
-- 
2.54.0