From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 10CB7384CE5 for ; Tue, 13 Oct 2026 08:22:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791879735; cv=none; b=o4PrHHb9QmcaUkilOL5cHKD9h03S1hnGPwk63ouljhA0KEKAULMY/GdeJ09G9ATCPNYQ3ivbBX16T14XbA6XYlxgjro5zZtxJm+Jfcgg3SFN4hP6hu475lA+eXF8eNM5BRbGPr85b/EsOFM5I/t91N68kNz6g+F3U05UCtWj6X0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791879735; c=relaxed/simple; bh=MuF8scdArSeE+ajqkntz75JHgOw46zNNK+gnOLPBPDo=; h=Message-ID:From:Subject:To:In-Reply-To:References:Content-Type: Date; b=MtYKV/aUpuk+CRfr8yX/aWJGMRie8F7DD1N6At4vW3V2abhjqIz3ZRDb57NzLiMBjPRSgHTP7xxZEcVkukMMvW3g2eSj+JrPGSMsTJMzFZvmbxIkzxhsNq/gMnkfbjE4TGpD7YVJvZDbylyOWA8VZaIm7g9r9bwA9v9n/I0D4CI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L0ZkwuOq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="L0ZkwuOq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCF041F000FF; Tue, 13 Oct 2026 08:22:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791879734; bh=SGJn5vuwlVMiJsIu31Won9qkddqB7F4jr9ynP8MNm2k=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=L0ZkwuOq06FR3fQvB0si9k+fQAftC25BRxCzB4aQmXUfwY105oj7dHyRtszDWPQtN KWWQgbKvlPHC6aUCoU5YUCp5LHlPAhVEUIdOCVtI8at8M2vT85UTlU8aC/7Akp3ntf CQeIxL4UnsNgZ22ccj3WgcPqL5pMNOnO+KFHcKU+S3uwYqXDTI9y7lDo4BeyUYUqPX pKc2p66Io/oSaP3uklr0AP3yb6ubgq2rDh3eVgakTEA93db0hymvAT6Pjf5K3wJL7r nC11fl1KI+WtaHi5Tyb7U29IrezQgJfBRE7F0f8fcwGaL/uOS4HVvDDveoUIhR1AMz JX/aOTg+A+tSg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH net-next v2 4/6] net: skbuff: replace __skb_frag_ref() with symmetric skb_netmem_ref() Reply-To: sashiko-reviews@lists.linux.dev To: "Mina Almasry" , linux-rdma@vger.kernel.org In-Reply-To: <20261012082148.1698596-5-almasrymina@google.com> References: <20261012082148.1698596-1-almasrymina@google.com> <20261012082148.1698596-5-almasrymina@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 13 Oct 2026 08:22:13 +0000 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Previously, __skb_frag_ref() and skb_frag_ref() unconditionally > incremented the non-pp backing refcount via get_netmem(), while > skb_frag_unref() decremented pp_ref_count whenever skb->pp_recycle was > set. Ref-ing a page_pool fragment into a pp_recycle=3D1 SKB (or clearing > pp_recycle=3D0 on an uncloned SKB while clones still held pp_recycle=3D1) > leaked the backing non-pp refcount and underflowed pp_ref_count across > IP-TFS, skb_split(), skb_shift(), and cloned unclone paths. >=20 > Replace __skb_frag_ref() with skb_netmem_ref(netmem, recycle) as the > exact counterpart to skb_netmem_unref(netmem, recycle): >=20 > - Keep skb->pp_recycle intact in skb_release_data() so uncloning paths > (pskb_expand_head() and pskb_carve_inside_{header,nonlinear}()) keep > trading pp_ref_count references symmetrically across clones. > - Propagate pp_recycle and call skb_frag_ref() on the destination SKB in > [ ... ] > Cc: Alexei Starovoitov > Cc: Jesper Dangaard Brouer > Cc: bpf@vger.kernel.org > Assisted-by: LLM > Signed-off-by: Mina Almasry Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261012082148.1698= 596-1-almasrymina@google.com?part=3D4