ALSA: hda/tas2781: leave hda_component in usable state
Commit Message
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>
---
sound/pci/hda/tas2781_hda_i2c.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
@@ -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[tas_priv->index].dev == dev) {
+ comps->dev = NULL;
+ strscpy(comps->name, "", sizeof(comps->name));
+ comps->playback_hook = NULL;
+ }
tasdevice_config_info_remove(tas_priv);
tasdevice_dsp_remove(tas_priv);