| Message ID | 20210416071147.2149109-1-thierry.reding@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] ASoC: simple-card-utils: Propagate errors on too many links | expand |
On 16/04/2021 08:11, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > The DAI counting code doesn't propagate errors when the number of > maximum links is exceeded, which causes subsequent initialization code > to continue to run and that eventually leads to memory corruption with > the code trying to access memory that is out of bounds. > > Fix this by propgating errors when the maximum number of links is s/propgating/propagating > reached, which ensures that the driver fails to load and prevents the > memory corruption. > > Fixes: f2138aed231c ("ASoC: simple-card-utils: enable flexible CPU/Codec/Platform") > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > sound/soc/generic/audio-graph-card.c | 19 +++++++++++-------- > sound/soc/generic/simple-card.c | 17 ++++++++++------- > 2 files changed, 21 insertions(+), 15 deletions(-) > > diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c > index 0582fe296471..2401212281c2 100644 > --- a/sound/soc/generic/audio-graph-card.c > +++ b/sound/soc/generic/audio-graph-card.c > @@ -539,8 +539,8 @@ static int graph_for_each_link(struct asoc_simple_priv *priv, > return ret; > } > > -static void graph_get_dais_count(struct asoc_simple_priv *priv, > - struct link_info *li); > +static int graph_get_dais_count(struct asoc_simple_priv *priv, > + struct link_info *li); > > int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev) > { > @@ -552,7 +552,10 @@ int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev) > card->dev = dev; > > memset(&li, 0, sizeof(li)); > - graph_get_dais_count(priv, &li); > + ret = graph_get_dais_count(priv, &li); > + if (ret < 0) > + return ret; > + > if (!li.link) > return -EINVAL; > > @@ -657,8 +660,8 @@ static int graph_count_dpcm(struct asoc_simple_priv *priv, > return 0; > } > > -static void graph_get_dais_count(struct asoc_simple_priv *priv, > - struct link_info *li) > +static int graph_get_dais_count(struct asoc_simple_priv *priv, > + struct link_info *li) > { > /* > * link_num : number of links. > @@ -706,9 +709,9 @@ static void graph_get_dais_count(struct asoc_simple_priv *priv, > * => 4 DAIs = 2xCPU + 2xCodec > * => 1 ccnf = 1xdummy-Codec > */ > - graph_for_each_link(priv, li, > - graph_count_noml, > - graph_count_dpcm); > + return graph_for_each_link(priv, li, > + graph_count_noml, > + graph_count_dpcm); > } > > int audio_graph_card_probe(struct snd_soc_card *card) > diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c > index bf5ddf1ea65f..1d1c4309b582 100644 > --- a/sound/soc/generic/simple-card.c > +++ b/sound/soc/generic/simple-card.c > @@ -526,8 +526,8 @@ static int simple_count_dpcm(struct asoc_simple_priv *priv, > return 0; > } > > -static void simple_get_dais_count(struct asoc_simple_priv *priv, > - struct link_info *li) > +static int simple_get_dais_count(struct asoc_simple_priv *priv, > + struct link_info *li) > { > struct device *dev = simple_priv_to_dev(priv); > struct device_node *top = dev->of_node; > @@ -584,12 +584,12 @@ static void simple_get_dais_count(struct asoc_simple_priv *priv, > li->num[0].platforms = 1; > > li->link = 1; > - return; > + return 0; > } > > - simple_for_each_link(priv, li, > - simple_count_noml, > - simple_count_dpcm); > + return simple_for_each_link(priv, li, > + simple_count_noml, > + simple_count_dpcm); > } > > static int simple_soc_probe(struct snd_soc_card *card) > @@ -628,7 +628,10 @@ static int asoc_simple_probe(struct platform_device *pdev) > card->probe = simple_soc_probe; > > memset(&li, 0, sizeof(li)); > - simple_get_dais_count(priv, &li); > + ret = simple_get_dais_count(priv, &li); > + if (ret < 0) > + return ret; > + > if (!li.link) > return -EINVAL; > > Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Thanks! Jon
On Fri, Apr 16, 2021 at 03:49:34PM +0100, Jon Hunter wrote: > > On 16/04/2021 08:11, Thierry Reding wrote: > > From: Thierry Reding <treding@nvidia.com> > > > > The DAI counting code doesn't propagate errors when the number of > > maximum links is exceeded, which causes subsequent initialization code > > to continue to run and that eventually leads to memory corruption with > > the code trying to access memory that is out of bounds. > > > > Fix this by propgating errors when the maximum number of links is > > s/propgating/propagating > > > reached, which ensures that the driver fails to load and prevents the > > memory corruption. > > > > Fixes: f2138aed231c ("ASoC: simple-card-utils: enable flexible CPU/Codec/Platform") > > Signed-off-by: Thierry Reding <treding@nvidia.com> Please delete unneeded context from mails when replying. Doing this makes it much easier to find your reply in the message, helping ensure it won't be missed by people scrolling through the irrelevant quoted material.
On Fri, 16 Apr 2021 09:11:46 +0200, Thierry Reding wrote: > The DAI counting code doesn't propagate errors when the number of > maximum links is exceeded, which causes subsequent initialization code > to continue to run and that eventually leads to memory corruption with > the code trying to access memory that is out of bounds. > > Fix this by propgating errors when the maximum number of links is > reached, which ensures that the driver fails to load and prevents the > memory corruption. Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next Thanks! [1/2] ASoC: simple-card-utils: Propagate errors on too many links commit: 0f687d826736a5b4eee03170382fe54d413b912a [2/2] ASoC: simple-card-utils: Increase maximum number of links to 128 commit: 343e55e71877415a23372388b3e0c59a9bba42f6 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
Hi Thierry > From: Thierry Reding <treding@nvidia.com> > > On Tegra186 and later, the number of links can go up to 72, so bump the > maximum number of links to the next power of two (128). > > Fixes: f2138aed231c ("ASoC: simple-card-utils: enable flexible CPU/Codec/Platform") > Signed-off-by: Thierry Reding <treding@nvidia.com> (snip) > +#define SNDRV_MAX_LINKS 128 > + > struct link_info { > int link; /* number of link */ > int cpu; /* turn for CPU / Codec */ > - struct prop_nums num[SNDRV_MINOR_DEVICES]; > + struct prop_nums num[SNDRV_MAX_LINKS]; > }; How many numbers do you really need ? Because simple-card needs many parameters, thus I will get below warning. # It is not yet happen on upstream kernel, but will be warning: the frame size of 2280 bytes is larger than 2048 bytes [-Wframe-larger-than=] This warning doesn't appear if SNDRV_MAX_LINKS was 64. Can we reduce it ? Thank you for your help !! Best regards --- Kuninori Morimoto
On Mon, Apr 19, 2021 at 10:42:55AM +0900, Kuninori Morimoto wrote: > > Hi Thierry > > > From: Thierry Reding <treding@nvidia.com> > > > > On Tegra186 and later, the number of links can go up to 72, so bump the > > maximum number of links to the next power of two (128). > > > > Fixes: f2138aed231c ("ASoC: simple-card-utils: enable flexible CPU/Codec/Platform") > > Signed-off-by: Thierry Reding <treding@nvidia.com> > (snip) > > +#define SNDRV_MAX_LINKS 128 > > + > > struct link_info { > > int link; /* number of link */ > > int cpu; /* turn for CPU / Codec */ > > - struct prop_nums num[SNDRV_MINOR_DEVICES]; > > + struct prop_nums num[SNDRV_MAX_LINKS]; > > }; > > > How many numbers do you really need ? As I mentioned in the commit message, the maximum I've seen is 72. Rounding up to the next power of two seemed like a good idea to give a bit of extra headroom. > Because simple-card needs many parameters, > thus I will get below warning. > # It is not yet happen on upstream kernel, but will be > > warning: the frame size of 2280 bytes is larger than 2048 bytes [-Wframe-larger-than=] > > This warning doesn't appear if SNDRV_MAX_LINKS was 64. > Can we reduce it ? Reducing from 128 to, say, 80 should eliminate that warning, but I wonder if perhaps a better solution for the longer term would be to allocate this structure on the heap rather than on the stack? That way we don't risk triggering this warning again in the future. The data structure seems to be only used during initialization, so something like a kzalloc()/kfree() pair doesn't seem like it would hurt much performance-wise. Add in the devm_ variants and the code complexity should also remain moderately low. Thierry
On Mon, Apr 19, 2021 at 04:51:42PM +0200, Thierry Reding wrote: > Reducing from 128 to, say, 80 should eliminate that warning, but I > wonder if perhaps a better solution for the longer term would be to > allocate this structure on the heap rather than on the stack? That > way we don't risk triggering this warning again in the future. > The data structure seems to be only used during initialization, so > something like a kzalloc()/kfree() pair doesn't seem like it would > hurt much performance-wise. Add in the devm_ variants and the code > complexity should also remain moderately low. Yes, that'd be much better - ideally we wouldn't have a fixed limit of any kind but that's a more involved change and quite possibly more trouble than it's worth.
Hi Thierry, Mark > > The data structure seems to be only used during initialization, so > > something like a kzalloc()/kfree() pair doesn't seem like it would > > hurt much performance-wise. Add in the devm_ variants and the code > > complexity should also remain moderately low. > > Yes, that'd be much better - ideally we wouldn't have a fixed limit of > any kind but that's a more involved change and quite possibly more > trouble than it's worth. Using "fixed array style" was very easy for me (*^o^*). OK, let's use kzalloc()/kfree() style. I can try it. Thank you for your help !! Best regards --- Kuninori Morimoto
diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c index 0582fe296471..2401212281c2 100644 --- a/sound/soc/generic/audio-graph-card.c +++ b/sound/soc/generic/audio-graph-card.c @@ -539,8 +539,8 @@ static int graph_for_each_link(struct asoc_simple_priv *priv, return ret; } -static void graph_get_dais_count(struct asoc_simple_priv *priv, - struct link_info *li); +static int graph_get_dais_count(struct asoc_simple_priv *priv, + struct link_info *li); int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev) { @@ -552,7 +552,10 @@ int audio_graph_parse_of(struct asoc_simple_priv *priv, struct device *dev) card->dev = dev; memset(&li, 0, sizeof(li)); - graph_get_dais_count(priv, &li); + ret = graph_get_dais_count(priv, &li); + if (ret < 0) + return ret; + if (!li.link) return -EINVAL; @@ -657,8 +660,8 @@ static int graph_count_dpcm(struct asoc_simple_priv *priv, return 0; } -static void graph_get_dais_count(struct asoc_simple_priv *priv, - struct link_info *li) +static int graph_get_dais_count(struct asoc_simple_priv *priv, + struct link_info *li) { /* * link_num : number of links. @@ -706,9 +709,9 @@ static void graph_get_dais_count(struct asoc_simple_priv *priv, * => 4 DAIs = 2xCPU + 2xCodec * => 1 ccnf = 1xdummy-Codec */ - graph_for_each_link(priv, li, - graph_count_noml, - graph_count_dpcm); + return graph_for_each_link(priv, li, + graph_count_noml, + graph_count_dpcm); } int audio_graph_card_probe(struct snd_soc_card *card) diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c index bf5ddf1ea65f..1d1c4309b582 100644 --- a/sound/soc/generic/simple-card.c +++ b/sound/soc/generic/simple-card.c @@ -526,8 +526,8 @@ static int simple_count_dpcm(struct asoc_simple_priv *priv, return 0; } -static void simple_get_dais_count(struct asoc_simple_priv *priv, - struct link_info *li) +static int simple_get_dais_count(struct asoc_simple_priv *priv, + struct link_info *li) { struct device *dev = simple_priv_to_dev(priv); struct device_node *top = dev->of_node; @@ -584,12 +584,12 @@ static void simple_get_dais_count(struct asoc_simple_priv *priv, li->num[0].platforms = 1; li->link = 1; - return; + return 0; } - simple_for_each_link(priv, li, - simple_count_noml, - simple_count_dpcm); + return simple_for_each_link(priv, li, + simple_count_noml, + simple_count_dpcm); } static int simple_soc_probe(struct snd_soc_card *card) @@ -628,7 +628,10 @@ static int asoc_simple_probe(struct platform_device *pdev) card->probe = simple_soc_probe; memset(&li, 0, sizeof(li)); - simple_get_dais_count(priv, &li); + ret = simple_get_dais_count(priv, &li); + if (ret < 0) + return ret; + if (!li.link) return -EINVAL;