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Subject[PATCH v2] ASoC: rt5640: Fix NULL dereference on module unload
Date
The rt5640->jack is NULL if jack is already disabled at the time of
driver's module unloading.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---

Changelog:

v2: - Addressed review comment from Takashi Iwai by making patch's diff a
bit cleaner and simpler.

- Addressed review comment from Mark Brown by removing noisy backtrace
from the commit's message and moving it after --- in order to keep it
discoverable in the ML archive.

Backtrace:

Unable to handle kernel NULL pointer dereference at virtual address 00000024
...
(rt5640_set_jack [snd_soc_rt5640])
(snd_soc_component_set_jack [snd_soc_core])
(soc_remove_component [snd_soc_core])
(soc_cleanup_card_resources [snd_soc_core])
(snd_soc_unregister_card [snd_soc_core])
(tegra_rt5640_remove [snd_soc_tegra_rt5640])
(platform_drv_remove)
(device_release_driver_internal)
(driver_detach)
(bus_remove_driver)
(tegra_rt5640_driver_exit
(sys_delete_module)

sound/soc/codecs/rt5640.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c
index adbae1f36a8a..747ca248bf10 100644
--- a/sound/soc/codecs/rt5640.c
+++ b/sound/soc/codecs/rt5640.c
@@ -2432,6 +2432,13 @@ static void rt5640_disable_jack_detect(struct snd_soc_component *component)
{
struct rt5640_priv *rt5640 = snd_soc_component_get_drvdata(component);

+ /*
+ * soc_remove_component() force-disables jack and thus rt5640->jack
+ * could be NULL at the time of driver's module unloading.
+ */
+ if (!rt5640->jack)
+ return;
+
disable_irq(rt5640->irq);
rt5640_cancel_work(rt5640);

--
2.24.0
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