Re: [RESEND PATCH ath-current 2/3] wifi: ath11k: fix NULL dereference in ahb remove when QMI init incomplete

[Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>]

On 7/30/2026 8:39 AM, Miaoqing Pan wrote:
> On WCN6750, if QMI messages never arrive (for example when qrtr_smd
> is not ready), WLAN initialization stops before the device is fully
> registered. In this case ATH11K_FLAG_QMI_FAIL is not set because no
> QMI event handler is executed.
> 
> When the driver is removed, ath11k_ahb_remove() still calls
> ath11k_core_deinit(), which eventually triggers
> ath11k_ce_cleanup_pipes() on uninitialized CE pipes and results in a
> NULL pointer dereference in ath11k_hal_srng_access_begin():
> 
>    ath11k_hal_srng_access_begin+0x14/0x68 [ath11k]
>    ath11k_ce_cleanup_pipes+0x184/0x190 [ath11k]
>    ath11k_pcic_stop+0x24/0x38 [ath11k]
>    ath11k_core_deinit+0xfc/0x1c0 [ath11k]
>    ath11k_ahb_remove+0x38/0xa0 [ath11k_ahb]
> 
> Fix this by invoking ath11k_ahb_remove_prepare() before the state
> check and skipping ath11k_core_deinit() when either QMI initialization
> failed or the device was never registered. If ATH11K_FLAG_REGISTERED
> is not set, core initialization did not complete and CE pipes may
> remain uninitialized, making ath11k_core_deinit() unsafe.
> 
> Tested-on: WCN6750 hw1.0 AHB WLAN.MSL.2.0.c2-00204-QCAMSLSWPLZ-1
> 
> Fixes: 00402f49d26f ("ath11k: Add support for WCN6750 device")
> Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
> ---
>   drivers/net/wireless/ath/ath11k/ahb.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
> index fb5640882b98..7f5f5c8d7c56 100644
> --- a/drivers/net/wireless/ath/ath11k/ahb.c
> +++ b/drivers/net/wireless/ath/ath11k/ahb.c
> @@ -1265,14 +1265,16 @@ static void ath11k_ahb_remove(struct platform_device *pdev)
>   {
>   	struct ath11k_base *ab = platform_get_drvdata(pdev);
>   
> -	if (test_bit(ATH11K_FLAG_QMI_FAIL, &ab->dev_flags)) {
> +	ath11k_ahb_remove_prepare(ab);
> +
> +	if (test_bit(ATH11K_FLAG_QMI_FAIL, &ab->dev_flags) ||
> +	    !test_bit(ATH11K_FLAG_REGISTERED, &ab->dev_flags)) {

Can we use ATH11K_FLAG_REGISTERED alone to decide the cleanup path? If 
REGISTERED is set, ath11k_core_qmi_firmware_ready() completed at least 
once and the normal ath11k_core_deinit() path should run. If QMI failed 
on recovery (say before FW_READY or INIT_DONE) this should still do 
core_deinit() isn't ?


>   		ath11k_ahb_power_down(ab, false);
>   		ath11k_debugfs_soc_destroy(ab);
>   		ath11k_qmi_deinit_service(ab);
>   		goto qmi_fail;
>   	}
>   
> -	ath11k_ahb_remove_prepare(ab);
>   	ath11k_core_deinit(ab);
>   
>   qmi_fail:



--
Ramesh