Re: [PATCH 2/2] mailbox: qcom-cpucp: handle NULL data in send_data callback
Dmitry Baryshkov <[email protected]>
| Newsgroups | dev.linux.lists.linux-rt-devel,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <gkju5hkg2r6nveirwe3bzeu6onezx5wxnkd6rxgn4lsp3uox2k@dn3crxwncft2> |
On Thu, Aug 06, 2026 at 03:03:57PM +0800, Jia Yang wrote:
> mailbox_clear_channel() calls mbox_send_message() with NULL data to
> notify the remote side that the RX channel has been cleared.
> qcom_cpucp_mbox_send_data() blindly dereferenced the data pointer,
> causing a NULL pointer dereference kernel panic when invoked from
> this path under PREEMPT_RT.
>
> Add an explicit NULL check and return early without writing to the
> TX register, which is the correct behaviour for a channel-clear
> notification.
>
> Fixes: 0e2a9a03106c ("mailbox: Add support for QTI CPUCP mailbox controller")
> Signed-off-by: Jia Yang <[email protected]>
> ---
> drivers/mailbox/qcom-cpucp-mbox.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
Reviewed-by: Dmitry Baryshkov <[email protected]>
--
With best wishes
Dmitry