alsa-devel.alsa-project.org archive mirror
 help / color / mirror / Atom feed
From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
	Bard Liao <bardliao@realtek.com>,
	Oder Chiou <oder_chiou@realtek.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Takashi Iwai <tiwai@suse.com>
Cc: linux-tegra@vger.kernel.org, alsa-devel@alsa-project.org,
	linux-kernel@vger.kernel.org
Subject: [alsa-devel] [PATCH v2] ASoC: rt5640: Fix NULL dereference on module unload
Date: Mon,  6 Jan 2020 04:47:07 +0300	[thread overview]
Message-ID: <20200106014707.11378-1-digetx@gmail.com> (raw)

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

_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel

             reply	other threads:[~2020-01-06  1:49 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-06  1:47 Dmitry Osipenko [this message]
2020-01-06 20:50 ` [alsa-devel] Applied "ASoC: rt5640: Fix NULL dereference on module unload" to the asoc tree Mark Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200106014707.11378-1-digetx@gmail.com \
    --to=digetx@gmail.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=bardliao@realtek.com \
    --cc=broonie@kernel.org \
    --cc=jonathanh@nvidia.com \
    --cc=lgirdwood@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=oder_chiou@realtek.com \
    --cc=perex@perex.cz \
    --cc=thierry.reding@gmail.com \
    --cc=tiwai@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).