[PATCH] ASoC: qcom: common: Fix refcounting in qcom_snd_parse_of()
There are two issues in this function.
1) We can't drop the refrences on "cpu", "codec" and "platform" before we take the reference. This doesn't cause a problem on the first iteration because those pointers start as NULL so the of_node_put() is a no-op. But on the subsequent iterations, it will lead to a use after free.
2) If the devm_kzalloc() allocation failed then the code returned directly instead of cleaning up.
Fixes: c1e6414cdc37 ("ASoC: qcom: common: Fix refcount imbalance on error") Fixes: 1e36ea360ab9 ("ASoC: qcom: common: use modern dai_link style") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com --- sound/soc/qcom/common.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/sound/soc/qcom/common.c b/sound/soc/qcom/common.c index 54660f126d09..09af00700700 100644 --- a/sound/soc/qcom/common.c +++ b/sound/soc/qcom/common.c @@ -58,7 +58,7 @@ int qcom_snd_parse_of(struct snd_soc_card *card) dlc = devm_kzalloc(dev, 2 * sizeof(*dlc), GFP_KERNEL); if (!dlc) { ret = -ENOMEM; - goto err; + goto err_put_np; }
link->cpus = &dlc[0]; @@ -70,7 +70,7 @@ int qcom_snd_parse_of(struct snd_soc_card *card) ret = of_property_read_string(np, "link-name", &link->name); if (ret) { dev_err(card->dev, "error getting codec dai_link name\n"); - goto err; + goto err_put_np; }
cpu = of_get_child_by_name(np, "cpu"); @@ -130,8 +130,10 @@ int qcom_snd_parse_of(struct snd_soc_card *card) } else { /* DPCM frontend */ dlc = devm_kzalloc(dev, sizeof(*dlc), GFP_KERNEL); - if (!dlc) - return -ENOMEM; + if (!dlc) { + ret = -ENOMEM; + goto err; + }
link->codecs = dlc; link->num_codecs = 1; @@ -158,10 +160,11 @@ int qcom_snd_parse_of(struct snd_soc_card *card)
return 0; err: - of_node_put(np); of_node_put(cpu); of_node_put(codec); of_node_put(platform); +err_put_np: + of_node_put(np); return ret; } EXPORT_SYMBOL(qcom_snd_parse_of);
On Thu, 5 Nov 2020 15:51:54 +0300, Dan Carpenter wrote:
There are two issues in this function.
- We can't drop the refrences on "cpu", "codec" and "platform" before we take the reference. This doesn't cause a problem on the first iteration because those pointers start as NULL so the of_node_put() is a no-op. But on the subsequent iterations, it will lead to a use after free.
[...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
Thanks!
[1/1] ASoC: qcom: common: Fix refcounting in qcom_snd_parse_of() commit: 4e59dd249cd513a211e2ecce2cb31f4e29a5ce5b
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.
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Thanks, Mark
participants (2)
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Dan Carpenter
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Mark Brown