On Mon, Jun 01, 2026 at 02:32:47PM -0400, Yuho Choi wrote:
> rpmsg_chrdev_probe() stores the newly allocated eptdev in the default
> endpoint's priv pointer before calling rpmsg_chrdev_eptdev_add(). If
> rpmsg_chrdev_eptdev_add() then fails, its error path frees eptdev while
> the default endpoint may still dispatch callbacks with the stale priv
> pointer.
>
> Avoid publishing eptdev through the default endpoint until
> rpmsg_chrdev_eptdev_add() succeeds. Messages received before the priv
> pointer is published should be ignored by rpmsg_ept_cb(). Flow-control
> updates can hit rpmsg_ept_flow_cb() in the same window, so make both
> callbacks return success when priv is NULL.
>
> Fixes: bc69d1066569 ("rpmsg: char: Introduce the "rpmsg-raw" channel")
> Signed-off-by: Yuho Choi <[email protected]>
> ---
> Changes in v2:
> - Use a 12-character Fixes SHA.
> - Drop the unnecessary asm-generic/rwonce.h include.
> - Handle NULL priv in rpmsg_ept_flow_cb() as well.
> drivers/rpmsg/rpmsg_char.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
Applied.
Thanks,
Mathieu
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> index ca9cf8858a5e..bff5aefee212 100644
> --- a/drivers/rpmsg/rpmsg_char.c
> +++ b/drivers/rpmsg/rpmsg_char.c
> @@ -104,6 +104,9 @@ static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void
> *buf, int len,
> struct rpmsg_eptdev *eptdev = priv;
> struct sk_buff *skb;
>
> + if (!eptdev)
> + return 0;
> +
> skb = alloc_skb(len, GFP_ATOMIC);
> if (!skb)
> return -ENOMEM;
> @@ -124,6 +127,9 @@ static int rpmsg_ept_flow_cb(struct rpmsg_device *rpdev,
> void *priv, bool enable
> {
> struct rpmsg_eptdev *eptdev = priv;
>
> + if (!eptdev)
> + return 0;
> +
> eptdev->remote_flow_restricted = enable;
> eptdev->remote_flow_updated = true;
>
> @@ -490,6 +496,7 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
> struct rpmsg_channel_info chinfo;
> struct rpmsg_eptdev *eptdev;
> struct device *dev = &rpdev->dev;
> + int ret;
>
> memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
> chinfo.src = rpdev->src;
> @@ -502,13 +509,17 @@ static int rpmsg_chrdev_probe(struct rpmsg_device
> *rpdev)
> /* Set the default_ept to the rpmsg device endpoint */
> eptdev->default_ept = rpdev->ept;
>
> + ret = rpmsg_chrdev_eptdev_add(eptdev, chinfo);
> +
> + if (ret)
> + return ret;
> /*
> * The rpmsg_ept_cb uses *priv parameter to get its rpmsg_eptdev
> context.
> - * Storedit in default_ept *priv field.
> + * Stored it in default_ept *priv field.
> */
> eptdev->default_ept->priv = eptdev;
>
> - return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
> + return 0;
> }
>
> static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
> --
> 2.43.0
>
