In some configurations, it's a requirement to split the probe in two, with a second part handled in a workqueue (e.g. for HDMI support which depends on the DRM modules).
SOF already handles these configurations but the error flow is incorrect. When an error occurs in the workqueue, the probe has technically already completed. If we release the resources on errors, this generates kernel oops/use-after-free when the resources are released a second time on module removal.
GitHub issue: https://github.com/thesofproject/linux/issues/945 Fixes: c16211d6226 ("ASoC: SOF: Add Sound Open Firmware driver core") Reviewed-by: Takashi Iwai tiwai@suse.de Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/soc/sof/core.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c index 693ad83bffc9..5beda47cdf9f 100644 --- a/sound/soc/sof/core.c +++ b/sound/soc/sof/core.c @@ -393,6 +393,7 @@ static int sof_probe_continue(struct snd_sof_dev *sdev)
return 0;
+#if !IS_ENABLED(CONFIG_SND_SOC_SOF_PROBE_WORK_QUEUE) fw_run_err: snd_sof_fw_unload(sdev); fw_load_err: @@ -401,6 +402,21 @@ static int sof_probe_continue(struct snd_sof_dev *sdev) snd_sof_free_debug(sdev); dbg_err: snd_sof_remove(sdev); +#else + + /* + * when the probe_continue is handled in a work queue, the + * probe does not fail so we don't release resources here. + * They will be released with an explicit call to + * snd_sof_device_remove() when the PCI/ACPI device is removed + */ + +fw_run_err: +fw_load_err: +ipc_err: +dbg_err: + +#endif
return ret; }