From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Date: Wed, 28 Dec 2022 21:47:01 +0530

Subject: [PATCH] bus: mhi: ep: Only send -ENOTCONN status if client driver is

 available

References: bsc#1012628

Patch-mainline: 6.2.3

Git-commit: e6cebcc27519dcf1652e604c73b9fd4f416987c0

commit e6cebcc27519dcf1652e604c73b9fd4f416987c0 upstream.

For the STOP and RESET commands, only send the channel disconnect status

-ENOTCONN if client driver is available. Otherwise, it will result in

null pointer dereference.

Cc: <stable@vger.kernel.org> # 5.19

Fixes: e827569062a8 ("bus: mhi: ep: Add support for processing command rings")

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>

Link: https://lore.kernel.org/r/20221228161704.255268-4-manivannan.sadhasivam@linaro.org

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/bus/mhi/ep/main.c | 16 ++++++++++------

 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c

index 1dc8a355..2b3a3b56 100644

--- a/drivers/bus/mhi/ep/main.c

+++ b/drivers/bus/mhi/ep/main.c

@@ -196,9 +196,11 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele

 		mhi_ep_mmio_disable_chdb(mhi_cntrl, ch_id);

 		/* Send channel disconnect status to client drivers */

-		result.transaction_status = -ENOTCONN;

-		result.bytes_xferd = 0;

-		mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);

+		if (mhi_chan->xfer_cb) {

+			result.transaction_status = -ENOTCONN;

+			result.bytes_xferd = 0;

+			mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);

+		}

 		/* Set channel state to STOP */

 		mhi_chan->state = MHI_CH_STATE_STOP;

@@ -228,9 +230,11 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele

 		mhi_ep_ring_reset(mhi_cntrl, ch_ring);

 		/* Send channel disconnect status to client driver */

-		result.transaction_status = -ENOTCONN;

-		result.bytes_xferd = 0;

-		mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);

+		if (mhi_chan->xfer_cb) {

+			result.transaction_status = -ENOTCONN;

+			result.bytes_xferd = 0;

+			mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);

+		}

 		/* Set channel state to DISABLED */

 		mhi_chan->state = MHI_CH_STATE_DISABLED;

-- 

2.35.3