[PATCH v3 6/6] rpmsg: char: Return error if user tries to destroy a default endpoint.

From: Arnaud Pouliquen
Date: Thu Apr 29 2021 - 09:56:00 EST


Using the RPMSG_DESTROY_EPT_IOCTL control, user application can
destroy an endpoint. This patch prevents to destroy a default endpoint
associated to a channel.

This update is needed to manage the "rpmsg-raw" channel. In this
case a default endpoint is used and destroying it without the
channel does not make sense.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
drivers/rpmsg/rpmsg_char.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 9166454c1310..f1cb352a59ed 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -282,6 +282,10 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
if (cmd != RPMSG_DESTROY_EPT_IOCTL)
return -EINVAL;

+ /* Don't allow to destroy a default endpoint. */
+ if (!eptdev->rpdev || eptdev->ept == eptdev->rpdev->ept)
+ return -EPERM;
+
return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
}

--
2.17.1