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 BD223568FDE for ; Wed, 14 Oct 2026 18:44:11 +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=1792003452; cv=none; b=h+sSjwAfjqi7Ww8E6dxKKM8RpIW6acy74j7TybyJ70ybS0Ix3TIqTm4a7aKuownf4d5tm7NHkcCRJJrhJdI5O6GZcK8dMHNYFY5ieSJtvb2wTMwOk5mqHg/VkQTRrq/sqPxarRqWz4EpqyjgpHQznLfrQrP4sCeKGw2XMQcosZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792003452; c=relaxed/simple; bh=4UE9QsUC5AxreApwBbojC2h7UTjRZAzukaH+jkcTlrc=; h=Message-ID:From:Subject:To:In-Reply-To:References:Content-Type: Date; b=uK673pHZ+0eUE010o0svgf6GVisVVEuKbTKaqgriE3Sfk8v5/amujUWC5AnvsqegPwhpIldomdjKPK99NB6izb3dSNtnKo5sil6dQ4KblGOYtZM1w3Qq5JONaezAgO/WvJhVzL34jNlXLUXUkxIGChlBb3/Pz6cyghzKbLBuVf4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oldOs7xP; 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="oldOs7xP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CB6F1F000C7; Wed, 14 Oct 2026 18:44:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792003451; bh=Nsc79lFYLRGMzt+YkJUklZjNTx88mJLNTfja+hwpJxE=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=oldOs7xPxOwRKX98s0xp/nU6vGid6Qg+hxAFNEO189gYcUDuLltfF2ESRsyw5kN6p yFY3DzaBJpKkSKYJ/HW91aGFSsqJgPo1TnDn8zgPpkWNfRWJT3UP5XkmXJ3uMT/+WR H4pNL4MHD3vseWgmuP3peWD+wywUDF9GPwxRUjC73NYMKpI3fs16/pthkdhUGr8vbe +9d6/T89858ES2XV+VYYOMhPaRmd2ApXSijM2PKQ6KiUAiVNXyi1i2Su/vhOC+QMsN m34Jo5zM8UrL0GgJzSOSqkWzXR+Tden/QkUCs0pRImhRibAR2M1zzxoK4Un9LxP+Cq nDAEo6Ux3S1LQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH net-next v3 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: <20261014173945.373295-5-almasrymina@google.com> References: <20261014173945.373295-1-almasrymina@google.com> <20261014173945.373295-5-almasrymina@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 14 Oct 2026 18:44:11 +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/20261014173945.3732= 95-1-almasrymina@google.com?part=3D4