Yes, Srinivas, agree with you, the error handling should be added during allocation.
Will submit the patch for it.
Thanks!
Best Regards,
Even Xu
-----Original Message-----
From: srinivas pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Sent: Wednesday, December 21, 2022 1:08 AM
To: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>; jikos@xxxxxxxxxx; benjamin.tissoires@xxxxxxxxxx; Xu, Even <even.xu@xxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] HID: intel_ish-hid: Add check for ishtp_dma_tx_map
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++) {
