| Message ID | 20190429182517.210909-1-zwisler@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0efa3334d65b7f421ba12382dfa58f6ff5bf83c4 |
| Headers | show |
| Series | [v2] ASoC: Intel: avoid Oops if DMA setup fails | expand |
On 4/29/19 1:25 PM, Ross Zwisler wrote: > 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@google.com> > Cc: stable@vger.kernel.org Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Thanks Ross! FWIW we should start deprecating this driver now and transition to SOF. I'll double-check how the upcoming 1.3 release works on my Pixel 2015/Samus device later this week. > --- > > Changes in v2: > - Upgraded the sst_dma_new() failure message from dev_warn() to dev_err() > (Pierre-Louis). > - Noted in the changelog that this change only affects Haswell and > Broadwell (Pierre-Louis). > > --- > sound/soc/intel/common/sst-firmware.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/sound/soc/intel/common/sst-firmware.c b/sound/soc/intel/common/sst-firmware.c > index 1e067504b6043..f830e59f93eaa 100644 > --- a/sound/soc/intel/common/sst-firmware.c > +++ b/sound/soc/intel/common/sst-firmware.c > @@ -1251,11 +1251,15 @@ 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); >
diff --git a/sound/soc/intel/common/sst-firmware.c b/sound/soc/intel/common/sst-firmware.c index 1e067504b6043..f830e59f93eaa 100644 --- a/sound/soc/intel/common/sst-firmware.c +++ b/sound/soc/intel/common/sst-firmware.c @@ -1251,11 +1251,15 @@ 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);
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@google.com> Cc: stable@vger.kernel.org --- Changes in v2: - Upgraded the sst_dma_new() failure message from dev_warn() to dev_err() (Pierre-Louis). - Noted in the changelog that this change only affects Haswell and Broadwell (Pierre-Louis). --- sound/soc/intel/common/sst-firmware.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)