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From: Stephen Hemminger <stephen@networkplumber.org>
To: Long Li <longli@microsoft.com>
Cc: dev@dpdk.org, weh@microsoft.com, stable@dpdk.org
Subject: Re: [PATCH] net/mana: fix CQE suppression handling on error completions
Date: Wed, 25 Mar 2026 11:54:51 -0700	[thread overview]
Message-ID: <20260325115451.4120982b@phoenix.local> (raw)
In-Reply-To: <20260325183836.1925080-1-longli@microsoft.com>

On Wed, 25 Mar 2026 11:38:36 -0700
Long Li <longli@microsoft.com> wrote:

> On error CQEs (e.g. SA_DROP), the hardware generates one CQE per WQE
> regardless of the suppression flag. The previous code honored the
> suppress_tx_cqe flag unconditionally, which caused it to skip reading
> error CQEs and misalign the CQ consumer index.
> 
> This misalignment causes subsequent completions to be misinterpreted:
> valid CQEs are read at wrong offsets, leading to spurious error
> counts, NULL packet frees, and potential use-after-free of mbufs
> that were already completed.
> 
> Check the CQE type before honoring suppression: only skip CQE reading
> when the completion is CQE_TX_OKAY.
> 
> Fixes: cce2c9df44 ("net/mana: suppress Tx CQE generation whenever possible")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Long Li <longli@microsoft.com>

Applied but needed to use longer SHA for Fixes to meet current guidelines.

Fixes: cce2c9df4481 ("net/mana: suppress Tx CQE generation whenever possible")

  reply	other threads:[~2026-03-25 18:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-25 18:38 [PATCH] net/mana: fix CQE suppression handling on error completions Long Li
2026-03-25 18:54 ` Stephen Hemminger [this message]
2026-03-25 18:56   ` [EXTERNAL] " Long Li

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