[alsa-devel] Applied "ASoC: SOF: fix fault at driver unload after failed probe" to the asoc tree

[Mark Brown]

The patch

   ASoC: SOF: fix fault at driver unload after failed probe

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.5

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From b06e46427f987bf83dcb6a69516b57276eb8ec0c Mon Sep 17 00:00:00 2001
From: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Date: Tue, 17 Dec 2019 18:05:16 -0600
Subject: [PATCH] ASoC: SOF: fix fault at driver unload after failed probe

If sof_machine_check() fails during driver probe, the IPC
state is not initialized and this will lead to a NULL
dereference at driver unload. Example log is as follows:

[ 1535.980630] sof-audio-pci 0000:00:1f.3: error: no matching ASoC machine driver found - aborting probe
[ 1535.980631] sof-audio-pci 0000:00:1f.3: error: failed to get machine info -19
[ 1535.980632] sof-audio-pci 0000:00:1f.3: error: sof_probe_work failed err: -19
[ 1550.798373] BUG: kernel NULL pointer dereference, address: 0000000000000008
...
[ 1550.798393] Call Trace:
[ 1550.798397]  snd_sof_ipc_free+0x15/0x30 [snd_sof]
[ 1550.798399]  snd_sof_device_remove+0x29/0xa0 [snd_sof]
[ 1550.798400]  sof_pci_remove+0x10/0x30 [snd_sof_pci]

Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Link: https://lore.kernel.org/r/20191218000518.5830-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/sof/ipc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/sof/ipc.c b/sound/soc/sof/ipc.c
index 5994e1073364..5fdfbaa8c4ed 100644
--- a/sound/soc/sof/ipc.c
+++ b/sound/soc/sof/ipc.c
@@ -826,6 +826,9 @@ void snd_sof_ipc_free(struct snd_sof_dev *sdev)
 {
 	struct snd_sof_ipc *ipc = sdev->ipc;
 
+	if (!ipc)
+		return;
+
 	/* disable sending of ipc's */
 	mutex_lock(&ipc->tx_mutex);
 	ipc->disable_ipc_tx = true;
-- 
2.20.1