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 --- 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 8b065a3cc848..7d68b00bdbcf 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -203,9 +203,11 @@ 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; @@ -235,9 +237,11 @@ 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;