From: Ross Zwisler <zwisler@xxxxxxxxxxxx>
commit 0efa3334d65b7f421ba12382dfa58f6ff5bf83c4 upstream.
Currently in sst_dsp_new() if we get an error return from sst_dma_new()
we just print an error message and then still complete the function
successfully. This means that we are trying to run without sst->dma
properly set up, which will result in NULL pointer dereference when
sst->dma is later used. This was happening for me in
sst_dsp_dma_get_channel():
struct sst_dma *dma = dsp->dma;
...
dma->ch = dma_request_channel(mask, dma_chan_filter, dsp);
This resulted in:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: sst_dsp_dma_get_channel+0x4f/0x125 [snd_soc_sst_firmware]
Fix this by adding proper error handling for the case where we fail to
set up DMA.
This change only affects Haswell and Broadwell systems. Baytrail
systems explicilty opt-out of DMA via sst->pdata->resindex_dma_base
being set to -1.
Signed-off-by: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
The upstream patch applied cleanly to all stable trees except
linux-4.4.y and linux-3.18.y. This is the backport for linux-4.4.y, and
the code I'm fixing was introduced in v4.0 so there is no need for a
linux-3.18.y backport.
The upstream patch is currently in Mark Brown's tree:
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/log/?h=for-next
Is that good enough, or should I resend after it's been merged in the
v5.2 merge window?
---
sound/soc/intel/common/sst-dsp.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/sound/soc/intel/common/sst-dsp.c b/sound/soc/intel/common/sst-dsp.c
index c9452e02e0dda..c0a50ecb6dbda 100644
--- a/sound/soc/intel/common/sst-dsp.c
+++ b/sound/soc/intel/common/sst-dsp.c
@@ -463,11 +463,15 @@ struct sst_dsp *sst_dsp_new(struct device *dev,
goto irq_err;
err = sst_dma_new(sst);
- if (err)
- dev_warn(dev, "sst_dma_new failed %d\n", err);
+ if (err) {
+ dev_err(dev, "sst_dma_new failed %d\n", err);
+ goto dma_err;
+ }
return sst;
+dma_err:
+ free_irq(sst->irq, sst);
irq_err:
if (sst->ops->free)
sst->ops->free(sst);
--
2.21.0.1020.gf2820cf01a-goog
