From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-5.sys.kth.se (smtp-5.sys.kth.se [130.237.48.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6482043F8C9; Mon, 5 Oct 2026 09:49:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=130.237.48.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791193759; cv=none; b=RrYOfao0kE1JkSNLjy+ITwp79BJudA4Jx9XDILUyNk7jMTd1ZMtEEJofVBND358ooELbvpU0kXHe6BEgpx0WIJmVPtju8LlKAlVtEiaReJqdhLPRGzVl3ky3JHFiJIJuOZWs30bkIpxH3hLOXDb1AvV9fSRHiX1aOLUM/riYgGo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791193759; c=relaxed/simple; bh=CkglMlUP4NpYuHrM6U1EbQ8jrt3KGi1JcmxfTf6Gpk0=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PJDRpSjjKLiA0SoP/+sX+oarO7ucOFugXLqIl43JWXnotkoaTw/xcAmLCN8PIeQtLqkFzKFWr52s4A0hFAZGx4ByI3/dHkJy8t3qEhW9GNsWLw0bY5K9wkrfGG3WnC+xqHzon1wAUdQVw+zdbvuafyjYYUODSUnhgOot7VrTOpU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kth.se; spf=pass smtp.mailfrom=kth.se; dkim=pass (1024-bit key) header.d=kth.se header.i=@kth.se header.b=FM0Waqp1; arc=none smtp.client-ip=130.237.48.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=kth.se Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kth.se Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=kth.se header.i=@kth.se header.b="FM0Waqp1" Received: from nargothrond (host-95-193-142-68.mobileonline.telia.com [95.193.142.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: sfle) by smtp-5.sys.kth.se (Postfix) with ESMTPSA id 4hyvjb5vqZzPNPw; Mon, 5 Oct 2026 11:49:07 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp-5.sys.kth.se 4hyvjb5vqZzPNPw DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kth.se; s=default; t=1791193750; bh=CkglMlUP4NpYuHrM6U1EbQ8jrt3KGi1JcmxfTf6Gpk0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FM0Waqp1m8lV1xj87nCHk2YotDUaGQhX7AqkjqWQJAkLjsoaJsGBlQFn72KNrkdeS 4kdllZz72xi4QO/sVjsILinRg9X8yLVBU6wXUA5jRpoIgArOQbYrbfzpl0aj5N9Hja nQfJkdTBw2tjcvzOYYrYFb0QJKzGFjD4nKFOFzlc= Date: Mon, 5 Oct 2026 11:49:05 +0200 From: Stefan Fleischmann To: Michael Chan , Eric Dumazet Cc: "David S . Miller" , Jakub Kicinski , Paolo Abeni , Simon Horman , netdev@vger.kernel.org, stable@vger.kernel.org, Eric Dumazet , Pavan Chebbi , Andrew Lunn Subject: Re: [PATCH net] bnxt_en: fix DMA mapping length for padded small packets Message-ID: <20261005114905.36ec94eb@nargothrond> In-Reply-To: References: <20261005023812.130639-1-edumazet@kernel.org> Organization: KTH X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sun, 4 Oct 2026 21:14:31 -0700 Michael Chan wrote: > On Sun, Oct 4, 2026 at 7:38=E2=80=AFPM Eric Dumazet > wrote: >=20 > > This issue was exposed after commit 447cbe95ebb9 ("vlan: fix > > skb_under_panic and races when toggling HW VLAN offload") because > > reserving extra VLAN headroom rounded LL_RESERVED_SPACE from 48 up > > to 64 bytes, shifting skb->data offsets and potentially causing > > small frames to land right against page boundaries. > > > > Fix this by using skb_put_padto(skb, BNXT_MIN_PKT_SIZE) in the > > normal_tx path. This ensures skb->len and skb_headlen(skb) reflect > > the padded size so that dma_map_single() maps the full buffer and > > the descriptor length is consistent. This also removes the > > temporary 'pad' variable and masking logic. > > > > Fixes: c0c050c58d84 ("bnxt_en: New Broadcom ethernet driver.") > > Cc: stable@vger.kernel.org > > Reported-by: Stefan Fleischmann > > Closes: > > https://lore.kernel.org/netdev/20261004122616.56714cbd@nargothrond/ > > Signed-off-by: Eric Dumazet =20 >=20 > Thanks. > Reviewed-by: Michael Chan Thanks a lot! I am testing the patch right now on 6.18.55. The system is already up for two hours without issues. Before the patch I couldn't get past 45 minutes without hitting the IOMMU DMA read fault. Best, Stefan