From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4C03A407594; Mon, 20 Apr 2026 13:27:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691633; cv=none; b=ReCdYbDtzSB3muqWfItB1rhZVCgqDIKVsIWDt04YbyiPyqnF214IZrb/8bxlC/7aiirNgJ1wm02jFLWEyvwjlqwxf40gNbOJ8bwqUU4TB9PsvcZ7CN4nlJJbSMksscst8jh/UFaQBaBYph4vMDtbdIy6M9xjeHmEVj2UchcAO2U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776691633; c=relaxed/simple; bh=EtbMov6KIzXcNw5LizLdDoNZDbLQdqxksZ2tpEZYjdw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mjnlTE+fOym5v3xpXhjqxqrmQ0kX4YTmvs3dKMZVVSPKw5hcLBbnw+d1aK2Xw28Gr0fETuiOAmQTmQe22VZBi9o+OVp4+/m28vLVKKzs8zd8yz8jI9H81OPg5E8wfFBdvwJMj0gJTxHxlt2i7o0WUB3bNT5+kTFKp45lXljYwIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BPbWJhrc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BPbWJhrc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B26EEC2BCB4; Mon, 20 Apr 2026 13:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776691633; bh=EtbMov6KIzXcNw5LizLdDoNZDbLQdqxksZ2tpEZYjdw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BPbWJhrcMizaShOlUcriXfokMb3hxJvdHf8WhTGWHbGzyzQ+tyypwWuq5R3U+OZOQ 0aF1AD+taw0RCoYPGXbGYwSnjbqecMWmRDjd4zBDnuNJIAEGgi75fZORABVfGXKb+K TpOJ8HwDHE2uV2t2slQ6QuXzPz/bQ7odvsGYwAOp+cOS+KaYIucX2+N/D/2H//i+OY OEpO48ko2okxAb72tcq4YTzIXcETV4OE3BQqga0JH1eaf8qyKmcFyaQu4Y+VRfaHOR SHezaApa02RPc1lQY+xQ/g5ripcJbKGKVmsCpBHFIc41c18xD56cYJpC4Bz4+RPYF3 bVWXxzUP12DXA== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Maciej Fijalkowski , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Stanislav Fomichev , Jakub Kicinski , Sasha Levin , magnus.karlsson@intel.com, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.18] xsk: tighten UMEM headroom validation to account for tailroom and min frame Date: Mon, 20 Apr 2026 09:18:57 -0400 Message-ID: <20260420132314.1023554-143-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420132314.1023554-1-sashal@kernel.org> References: <20260420132314.1023554-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.18.23 Content-Transfer-Encoding: 8bit From: Maciej Fijalkowski [ Upstream commit a315e022a72d95ef5f1d4e58e903cb492b0ad931 ] The current headroom validation in xdp_umem_reg() could leave us with insufficient space dedicated to even receive minimum-sized ethernet frame. Furthermore if multi-buffer would come to play then skb_shared_info stored at the end of XSK frame would be corrupted. HW typically works with 128-aligned sizes so let us provide this value as bare minimum. Multi-buffer setting is known later in the configuration process so besides accounting for 128 bytes, let us also take care of tailroom space upfront. Reviewed-by: Björn Töpel Acked-by: Stanislav Fomichev Fixes: 99e3a236dd43 ("xsk: Add missing check on user supplied headroom size") Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-2-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Error: Failed to generate final synthesis net/xdp/xdp_umem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 9f76ca591d54f..9ec7bd948acc7 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -202,7 +202,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) if (!unaligned_chunks && chunks_rem) return -EINVAL; - if (headroom >= chunk_size - XDP_PACKET_HEADROOM) + if (headroom > chunk_size - XDP_PACKET_HEADROOM - + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) - 128) return -EINVAL; if (mr->flags & XDP_UMEM_TX_METADATA_LEN) { -- 2.53.0