On 9/17/24 4:09 PM, Felix Fietkau wrote:
> If mcu_skb_prepare_msg is not implemented, incrementing skb refcount does not
> work for mcu message retry. In some cases (e.g. on SDIO), shared skbs can trigger
> a BUG_ON, crashing the system.
> Fix this by only incrementing refcount if retry is actually supported.
>
> Fixes: 3688c18b65ae ("wifi: mt76: mt7915: retry mcu messages")
> Reported-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx> #KernelCI
> Tested-by: Alper Nebi Yasak <alpernebiyasak@xxxxxxxxx>
> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> ---
> drivers/net/wireless/mediatek/mt76/mcu.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mcu.c b/drivers/net/wireless/mediatek/mt76/mcu.c
> index 98da82b74094..3353012e8542 100644
> --- a/drivers/net/wireless/mediatek/mt76/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mcu.c
> @@ -84,13 +84,16 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
> mutex_lock(&dev->mcu.mutex);
>
> if (dev->mcu_ops->mcu_skb_prepare_msg) {
> + orig_skb = skb;
> ret = dev->mcu_ops->mcu_skb_prepare_msg(dev, skb, cmd, &seq);
> if (ret < 0)
> goto out;
> }
>
> retry:
> - orig_skb = skb_get(skb);
> + /* orig skb might be needed for retry, mcu_skb_send_msg consumes it */
> + if (orig_skb)
> + skb_get(orig_skb);
> ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, &seq);
> if (ret < 0)
> goto out;
> @@ -105,7 +108,7 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
> do {
> skb = mt76_mcu_get_response(dev, expires);
> if (!skb && !test_bit(MT76_MCU_RESET, &dev->phy.state) &&
> - retry++ < dev->mcu_ops->max_retry) {
> + orig_skb && retry++ < dev->mcu_ops->max_retry) {
> dev_err(dev->dev, "Retry message %08x (seq %d)\n",
> cmd, seq);
> skb = orig_skb;
This patch is in next from 5 weeks. As 3688c18b65ae ("wifi: mt76: mt7915: retry mcu messages") is
already in the mainline, why this fix hasn't been included in mainline? I thought fixes are included
as soon as possible in mainline RCs. Am I missing something?
Are we planning to include this fix in next release instead of current one?
--
BR,
Muhammad Usama Anjum
