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From: Greg KH <gregkh@linuxfoundation.org>
To: WenTao Liang <vulab@iscas.ac.cn>
Cc: ntb@lists.linux.dev, jdmason@kudzu.us, dave.jiang@intel.com,
	allenbh@gmail.com, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH v2] ntb: fix tx descriptor leak on dmaengine_submit failure
Date: Mon, 29 Jun 2026 06:37:11 +0200	[thread overview]
Message-ID: <2026062901-slather-filing-3fc4@gregkh> (raw)
In-Reply-To: <20260628083301.9781-1-vulab@iscas.ac.cn>

On Sun, Jun 28, 2026 at 04:33:01PM +0800, WenTao Liang wrote:
> When dmaengine_submit fails after dma_set_unmap has been called, the
> error path err_set_unmap only calls dmaengine_unmap_put once, but the
> unmap object has two references (one from dmaengine_get_unmap_data and
> one from dma_set_unmap held by the tx descriptor). The tx descriptor
> itself is never freed, so its reference to unmap is never released,
> causing a kref leak and a dangling pointer in the freed descriptor.
> 
> Replace dmaengine_unmap_put with dmaengine_desc_put(txd) in the
> err_set_unmap path to properly release the tx descriptor, which will also
> drop the unmap reference it holds.
> 
> Suggested-by: Greg KH <gregkh@linuxfoundation.org>

No, I didn't suggest ANY of these patches.

Also you did not use Assisted-by:, why?

Please start small with just 1 patch that you can do properly, before
flooding us with lots.

Please go and reply to all of these where you incorrectly added my
suggested-by and ask for them to be dropped.

greg k-h

      reply	other threads:[~2026-06-29  4:38 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-28  8:33 [PATCH v2] ntb: fix tx descriptor leak on dmaengine_submit failure WenTao Liang
2026-06-29  4:37 ` Greg KH [this message]

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