[PATCH v3 1/9] firmware: arm_scmi: Fix double free in OPTEE transport

[Cristian Marussi]

Channels can be shared between protocols, avoid freeing the same channel
descriptors twice when unloading the stack.

Fixes: 5f90f189a052 ("firmware: arm_scmi: Add optee transport")
Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
 drivers/firmware/arm_scmi/optee.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index 4e7944b91e38..0c8908d3b1d6 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -473,6 +473,13 @@ static int scmi_optee_chan_free(int id, void *p, void *data)
 	struct scmi_chan_info *cinfo = p;
 	struct scmi_optee_channel *channel = cinfo->transport_info;
 
+	/*
+	 * Different protocols might share the same chan info, so a previous
+	 * call might have already freed the structure.
+	 */
+	if (!channel)
+		return 0;
+
 	mutex_lock(&scmi_optee_private->mu);
 	list_del(&channel->link);
 	mutex_unlock(&scmi_optee_private->mu);
-- 
2.45.2