On Tue, 2022-11-22 at 21:48 +0800, Jiasheng Jiang wrote: > As the kcalloc may return NULL pointer, > it should be better to check the ishtp_dma_tx_map > before use in order to avoid NULL pointer dereference. > > Fixes: 3703f53b99e4 ("HID: intel_ish-hid: ISH Transport layer") > Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > --- +Even Xu, We should do during alloc. Please try to submit a change for that for later kernel rev as it will require error processing during hbm dispatch. > drivers/hid/intel-ish-hid/ishtp/dma-if.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/hid/intel-ish-hid/ishtp/dma-if.c > b/drivers/hid/intel-ish-hid/ishtp/dma-if.c > index 40554c8daca0..00046cbfd4ed 100644 > --- a/drivers/hid/intel-ish-hid/ishtp/dma-if.c > +++ b/drivers/hid/intel-ish-hid/ishtp/dma-if.c > @@ -104,6 +104,11 @@ void *ishtp_cl_get_dma_send_buf(struct > ishtp_device *dev, > int required_slots = (size / DMA_SLOT_SIZE) > + 1 * (size % DMA_SLOT_SIZE != 0); > > + if (!dev->ishtp_dma_tx_map) { > + dev_err(dev->devc, "Fail to allocate Tx map\n"); > + return NULL; > + } > + > spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); > for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); > i++) { > free = 1; > @@ -150,6 +155,11 @@ void ishtp_cl_release_dma_acked_mem(struct > ishtp_device *dev, > return; > } > > + if (!dev->ishtp_dma_tx_map) { > + dev_err(dev->devc, "Fail to allocate Tx map\n"); > + return; > + } > + > i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE; > spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); > for (j = 0; j < acked_slots; j++) {