6.6-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 23261f0de09427367e99f39f588e31e2856a690e upstream.
The reference taken to the sync provider OF node when probing the platform device is currently only dropped if the set_sync() callback fails during DAI probe.
Make sure to drop the reference on platform probe failures (e.g. probe deferral) and on driver unbind.
This also avoids a potential use-after-free in case the DAI is ever reprobed without first rebinding the platform driver.
Fixes: 5914d285f6b7 ("ASoC: stm32: sai: Add synchronization support") Fixes: d4180b4c02e7 ("ASoC: stm32: sai: fix set_sync service") Cc: Olivier Moysan olivier.moysan@st.com Cc: stable@vger.kernel.org # 4.16: d4180b4c02e7 Signed-off-by: Johan Hovold johan@kernel.org Reviewed-by: olivier moysan olivier.moysan@foss.st.com Link: https://patch.msgid.link/20251124104908.15754-4-johan@kernel.org Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/soc/stm/stm32_sai.c | 12 +++--------- sound/soc/stm/stm32_sai_sub.c | 23 ++++++++++++++++------- 2 files changed, 19 insertions(+), 16 deletions(-)
--- a/sound/soc/stm/stm32_sai.c +++ b/sound/soc/stm/stm32_sai.c @@ -122,7 +122,6 @@ static int stm32_sai_set_sync(struct stm if (!pdev) { dev_err(&sai_client->pdev->dev, "Device not found for node %pOFn\n", np_provider); - of_node_put(np_provider); return -ENODEV; }
@@ -131,21 +130,16 @@ static int stm32_sai_set_sync(struct stm if (!sai_provider) { dev_err(&sai_client->pdev->dev, "SAI sync provider data not found\n"); - ret = -EINVAL; - goto error; + return -EINVAL; }
/* Configure sync client */ ret = stm32_sai_sync_conf_client(sai_client, synci); if (ret < 0) - goto error; + return ret;
/* Configure sync provider */ - ret = stm32_sai_sync_conf_provider(sai_provider, synco); - -error: - of_node_put(np_provider); - return ret; + return stm32_sai_sync_conf_provider(sai_provider, synco); }
static int stm32_sai_probe(struct platform_device *pdev) --- a/sound/soc/stm/stm32_sai_sub.c +++ b/sound/soc/stm/stm32_sai_sub.c @@ -1453,7 +1453,8 @@ static int stm32_sai_sub_parse_of(struct dev_err(&pdev->dev, "External synchro not supported\n"); of_node_put(args.np); - return -EINVAL; + ret = -EINVAL; + goto err_put_sync_provider; } sai->sync = SAI_SYNC_EXTERNAL;
@@ -1462,7 +1463,8 @@ static int stm32_sai_sub_parse_of(struct (sai->synci > (SAI_GCR_SYNCIN_MAX + 1))) { dev_err(&pdev->dev, "Wrong SAI index\n"); of_node_put(args.np); - return -EINVAL; + ret = -EINVAL; + goto err_put_sync_provider; }
if (of_property_match_string(args.np, "compatible", @@ -1476,7 +1478,8 @@ static int stm32_sai_sub_parse_of(struct if (!sai->synco) { dev_err(&pdev->dev, "Unknown SAI sub-block\n"); of_node_put(args.np); - return -EINVAL; + ret = -EINVAL; + goto err_put_sync_provider; } }
@@ -1486,13 +1489,15 @@ static int stm32_sai_sub_parse_of(struct
of_node_put(args.np); sai->sai_ck = devm_clk_get(&pdev->dev, "sai_ck"); - if (IS_ERR(sai->sai_ck)) - return dev_err_probe(&pdev->dev, PTR_ERR(sai->sai_ck), - "Missing kernel clock sai_ck\n"); + if (IS_ERR(sai->sai_ck)) { + ret = dev_err_probe(&pdev->dev, PTR_ERR(sai->sai_ck), + "Missing kernel clock sai_ck\n"); + goto err_put_sync_provider; + }
ret = clk_prepare(sai->pdata->pclk); if (ret < 0) - return ret; + goto err_put_sync_provider;
if (STM_SAI_IS_F4(sai->pdata)) return 0; @@ -1514,6 +1519,8 @@ static int stm32_sai_sub_parse_of(struct
err_unprepare_pclk: clk_unprepare(sai->pdata->pclk); +err_put_sync_provider: + of_node_put(sai->np_sync_provider);
return ret; } @@ -1584,6 +1591,7 @@ static int stm32_sai_sub_probe(struct pl
err_unprepare_pclk: clk_unprepare(sai->pdata->pclk); + of_node_put(sai->np_sync_provider);
return ret; } @@ -1596,6 +1604,7 @@ static void stm32_sai_sub_remove(struct snd_dmaengine_pcm_unregister(&pdev->dev); snd_soc_unregister_component(&pdev->dev); pm_runtime_disable(&pdev->dev); + of_node_put(sai->np_sync_provider); }
#ifdef CONFIG_PM_SLEEP