6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Richard Fitzgerald rf@opensource.cirrus.com
[ Upstream commit 62412a9357b16a4e39dc582deb2e2a682b92524c ]
Add a check to cs_dsp_coeff_write_ctrl() to abort if the control is not writeable.
The cs_dsp code originated as an ASoC driver (wm_adsp) where all controls were exported as ALSA controls. It relied on ALSA to enforce the read-only permission. Now that the code has been separated from ALSA/ASoC it must perform its own permission check.
This isn't currently causing any problems so there shouldn't be any need to backport this. If the client of cs_dsp exposes the control as an ALSA control, it should set permissions on that ALSA control to protect it. The few uses of cs_dsp_coeff_write_ctrl() inside drivers are for writable controls.
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com Link: https://patch.msgid.link/20240702110809.16836-1-rf@opensource.cirrus.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/cirrus/cs_dsp.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c index 8a347b938406..89fd63205a6e 100644 --- a/drivers/firmware/cirrus/cs_dsp.c +++ b/drivers/firmware/cirrus/cs_dsp.c @@ -796,6 +796,9 @@ int cs_dsp_coeff_write_ctrl(struct cs_dsp_coeff_ctl *ctl,
lockdep_assert_held(&ctl->dsp->pwr_lock);
+ if (ctl->flags && !(ctl->flags & WMFW_CTL_FLAG_WRITEABLE)) + return -EPERM; + if (len + off * sizeof(u32) > ctl->len) return -EINVAL;