2023-07-17 17:15:52

by Bjorn Andersson

Subject: [PATCH] rpmsg: glink: Avoid dereferencing NULL channel

The newly introduced signal command handler checks for non-existing
channel and print an error message, but then continues on to dereference
that same channel.

Instead abort the handler when no channel is found.

Fixes: a2b73aa512a4 ("rpmsg: glink: Add support to handle signals command")
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Signed-off-by: Bjorn Andersson <[email protected]>
---
drivers/rpmsg/qcom_glink_native.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index e10c05ed21bb..82d460ff4777 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -1070,8 +1070,10 @@ static void qcom_glink_handle_signals(struct qcom_glink *glink,
spin_lock_irqsave(&glink->idr_lock, flags);
channel = idr_find(&glink->rcids, rcid);
spin_unlock_irqrestore(&glink->idr_lock, flags);
- if (!channel)
+ if (!channel) {
dev_err(glink->dev, "signal for non-existing channel\n");
+ return;
+ }

enable = sigs & NATIVE_DSR_SIG || sigs & NATIVE_CTS_SIG;

--
2.25.1

2023-07-18 16:34:31

by Mathieu Poirier

Subject: Re: [PATCH] rpmsg: glink: Avoid dereferencing NULL channel

On Mon, Jul 17, 2023 at 09:55:38AM -0700, Bjorn Andersson wrote:
> The newly introduced signal command handler checks for non-existing
> channel and print an error message, but then continues on to dereference
> that same channel.
>
> Instead abort the handler when no channel is found.
>
> Fixes: a2b73aa512a4 ("rpmsg: glink: Add support to handle signals command")
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
> Closes: https://lore.kernel.org/r/[email protected]/
> Signed-off-by: Bjorn Andersson <[email protected]>
> ---
> drivers/rpmsg/qcom_glink_native.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
> index e10c05ed21bb..82d460ff4777 100644
> --- a/drivers/rpmsg/qcom_glink_native.c
> +++ b/drivers/rpmsg/qcom_glink_native.c
> @@ -1070,8 +1070,10 @@ static void qcom_glink_handle_signals(struct qcom_glink *glink,
> spin_lock_irqsave(&glink->idr_lock, flags);
> channel = idr_find(&glink->rcids, rcid);
> spin_unlock_irqrestore(&glink->idr_lock, flags);
> - if (!channel)
> + if (!channel) {
> dev_err(glink->dev, "signal for non-existing channel\n");
> + return;
> + }

I have applied this patch.

Thanks,
Mathieu

>
> enable = sigs & NATIVE_DSR_SIG || sigs & NATIVE_CTS_SIG;
>
> --
> 2.25.1
>