Subject: Re: [PATCH] rtl8xxxu: avoid parsing short RX packet

From: Kalle Valo <[email-masked]>
Date: Sat, 19 Jun 2021 09:06:19 +0000 (UTC)

Íñigo Huguet <[email-masked]> wrote:

> One USB data buffer can contain multiple received network
> packets. If that's the case, they're processed this way:
> 1. Original buffer is cloned
> 2. Original buffer is trimmed to contain only the first
>    network packet
> 3. This first network packet is passed to network stack
> 4. Cloned buffer is trimmed to eliminate the first network
>    packet
> 5. Repeat with the cloned buffer until there are no more
>    network packets inside
> 
> However, if the space remaining in original buffer after
> the first network packet is not enough to contain at least
> another network packet descriptor, it is not cloned.
> 
> The loop parsing this packets ended if remaining space == 0.
> But if the remaining space was > 0 but < packet descriptor
> size, another iteration of the loop was done, processing again
> the previous packet because cloning didn't happen. Moreover,
> the ownership of this packet had been passed to network
> stack in the previous iteration.
> 
> This patch ensures that no extra iteration is done if the
> remaining size is not enough for one packet, and also avoid
> the first iteration for the same reason.
> 
> Probably this doesn't happen in practice, but can happen
> theoretically.
> 
> Signed-off-by: Íñigo Huguet <[email-masked]>

Patch applied to wireless-drivers-next.git, thanks.

adf6a0f8c0a6 rtl8xxxu: avoid parsing short RX packet

-- 
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