From 75a25d31b80770485641ad2789a854955f5c1e40 Mon Sep 17 00:00:00 2001
From: Gergo Koteles <soyer@irl.hu>
Date: Sat, 9 Dec 2023 22:18:29 +0100
Subject: [PATCH] ALSA: hda/tas2781: leave hda_component in usable state
Git-commit: 75a25d31b80770485641ad2789a854955f5c1e40
Patch-mainline: v6.7-rc6
References: git-fixes
Unloading then loading the module causes a NULL ponter dereference.
The hda_unbind zeroes the hda_component, later the hda_bind tries
to dereference the codec field.
The hda_component is only initialized once by tas2781_generic_fixup.
Set only previously modified fields to NULL.
Bug: kernel NULL pointer dereference, address: 0000000000000322
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? exc_page_fault+0x7f/0x180
? asm_exc_page_fault+0x26/0x30
? tas2781_hda_bind+0x59/0x140 [snd_hda_scodec_tas2781_i2c]
component_bind_all+0xf3/0x240
try_to_bring_up_aggregate_device+0x1c3/0x270
__component_add+0xbc/0x1a0
tas2781_hda_i2c_probe+0x289/0x3a0 [snd_hda_scodec_tas2781_i2c]
i2c_device_probe+0x136/0x2e0
Fixes: 5be27f1e3ec9 ("ALSA: hda/tas2781: Add tas2781 HDA driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gergo Koteles <soyer@irl.hu>
Link: https://lore.kernel.org/r/8b8ed2bd5f75fbb32e354a3226c2f966fa85b46b.1702156522.git.soyer@irl.hu
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/pci/hda/tas2781_hda_i2c.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/sound/pci/hda/tas2781_hda_i2c.c b/sound/pci/hda/tas2781_hda_i2c.c
index fb802802939e..b42837105c22 100644
--- a/sound/pci/hda/tas2781_hda_i2c.c
+++ b/sound/pci/hda/tas2781_hda_i2c.c
@@ -612,9 +612,13 @@ static void tas2781_hda_unbind(struct device *dev,
{
struct tasdevice_priv *tas_priv = dev_get_drvdata(dev);
struct hda_component *comps = master_data;
+ comps = &comps[tas_priv->index];
- if (comps[tas_priv->index].dev == dev)
- memset(&comps[tas_priv->index], 0, sizeof(*comps));
+ if (comps->dev == dev) {
+ comps->dev = NULL;
+ memset(comps->name, 0, sizeof(comps->name));
+ comps->playback_hook = NULL;
+ }
tasdevice_config_info_remove(tas_priv);
tasdevice_dsp_remove(tas_priv);
--
2.35.3