From: Kean Ren <rh_king@163.com>
To: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Maciej Strozek <mstrozek@opensource.cirrus.com>,
Bard Liao <yung-chuan.liao@linux.intel.com>,
Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>,
Liam Girdwood <lgirdwood@gmail.com>,
Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>,
Takashi Iwai <tiwai@suse.com>, Vinod Koul <vkoul@kernel.org>,
Peter Ujfalusi <peter.ujfalusi@linux.intel.com>,
linux-sound@vger.kernel.org, patches@opensource.cirrus.com,
linux-kernel@vger.kernel.org, Kean Ren <rh_king@163.com>
Subject: [PATCH] ASoC: SDCA: fix NULL pointer dereference in sdca_dev_unregister_functions
Date: Thu, 11 Jun 2026 10:37:57 +0800 [thread overview]
Message-ID: <20260611023757.1553960-1-rh_king@163.com> (raw)
sdca_dev_unregister_functions() iterates over all SDCA function
descriptors and calls sdca_dev_unregister() on each func_dev without
checking for NULL. When a function registration has failed partway
through, or the device cleanup races with probe deferral, func_dev
entries may be NULL, leading to a kernel oops:
BUG: kernel NULL pointer dereference, address: 0000000000000040
RIP: 0010:device_del+0x1e/0x3e0
Call Trace:
sdca_dev_unregister_functions+0x37/0x60 [snd_soc_sdca]
release_nodes+0x35/0xb0
devres_release_all+0x90/0x100
device_unbind_cleanup+0xe/0x80
device_release_driver_internal+0x1c1/0x200
bus_remove_device+0xc6/0x130
device_del+0x161/0x3e0
device_unregister+0x17/0x60
sdw_delete_slave+0xb6/0xd0 [soundwire_bus]
sdw_bus_master_delete+0x1e/0x50 [soundwire_bus]
...
sof_probe_work+0x19/0x30 [snd_sof]
This was observed on a Lenovo ThinkPad X1 Carbon G14 (Panther Lake)
with the SOF audio driver probe failing due to missing Panther Lake
firmware, causing the subsequent cleanup of SoundWire devices to
trigger the crash.
Fix this with three changes:
1) Add a NULL guard in sdca_dev_unregister() so that callers do not
need to pre-validate the pointer (defense in depth).
2) In sdca_dev_unregister_functions(), skip NULL func_dev entries
and clear func_dev to NULL after unregistration, making the
function idempotent and safe against double-invocation.
3) In sdca_dev_register_functions(), roll back all previously
registered functions when a later one fails, so the function
array is never left in a partially-populated state.
Fixes: 4496d1c65bad ("ASoC: SDCA: add function devices")
Signed-off-by: Kean Ren <rh_king@163.com>
---
sound/soc/sdca/sdca_function_device.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/sound/soc/sdca/sdca_function_device.c b/sound/soc/sdca/sdca_function_device.c
index feacfbc6a518..b5ca98283a88 100644
--- a/sound/soc/sdca/sdca_function_device.c
+++ b/sound/soc/sdca/sdca_function_device.c
@@ -82,6 +82,9 @@ static struct sdca_dev *sdca_dev_register(struct device *parent,
static void sdca_dev_unregister(struct sdca_dev *sdev)
{
+ if (!sdev)
+ return;
+
auxiliary_device_delete(&sdev->auxdev);
auxiliary_device_uninit(&sdev->auxdev);
}
@@ -90,14 +93,24 @@ int sdca_dev_register_functions(struct sdw_slave *slave)
{
struct sdca_device_data *sdca_data = &slave->sdca_data;
int i;
+ int ret;
for (i = 0; i < sdca_data->num_functions; i++) {
struct sdca_dev *func_dev;
func_dev = sdca_dev_register(&slave->dev,
&sdca_data->function[i]);
- if (IS_ERR(func_dev))
- return PTR_ERR(func_dev);
+ if (IS_ERR(func_dev)) {
+ ret = PTR_ERR(func_dev);
+ /*
+ * Unregister functions that were successfully
+ * registered before this failure. This also
+ * sets func_dev to NULL so the caller will not
+ * try to unregister them again.
+ */
+ sdca_dev_unregister_functions(slave);
+ return ret;
+ }
sdca_data->function[i].func_dev = func_dev;
}
@@ -111,7 +124,12 @@ void sdca_dev_unregister_functions(struct sdw_slave *slave)
struct sdca_device_data *sdca_data = &slave->sdca_data;
int i;
- for (i = 0; i < sdca_data->num_functions; i++)
+ for (i = 0; i < sdca_data->num_functions; i++) {
+ if (!sdca_data->function[i].func_dev)
+ continue;
+
sdca_dev_unregister(sdca_data->function[i].func_dev);
+ sdca_data->function[i].func_dev = NULL;
+ }
}
EXPORT_SYMBOL_NS(sdca_dev_unregister_functions, "SND_SOC_SDCA");
--
2.47.3
next reply other threads:[~2026-06-11 2:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-11 2:37 Kean Ren [this message]
2026-06-11 9:07 ` [PATCH] ASoC: SDCA: fix NULL pointer dereference in sdca_dev_unregister_functions Charles Keepax
2026-06-11 14:55 ` 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=20260611023757.1553960-1-rh_king@163.com \
--to=rh_king@163.com \
--cc=broonie@kernel.org \
--cc=ckeepax@opensource.cirrus.com \
--cc=lgirdwood@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sound@vger.kernel.org \
--cc=mstrozek@opensource.cirrus.com \
--cc=patches@opensource.cirrus.com \
--cc=perex@perex.cz \
--cc=peter.ujfalusi@linux.intel.com \
--cc=pierre-louis.bossart@linux.dev \
--cc=tiwai@suse.com \
--cc=vkoul@kernel.org \
--cc=yung-chuan.liao@linux.intel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.