From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BD12F3A453B for ; Wed, 22 Apr 2026 03:37:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776829042; cv=none; b=hUIJ2iku/G+aG0i1IDVEJfyMpcaoZAcz+ztV2ErnFvpS2IYkiH2/tATf2xSYGT7wzQ8quhd38WB/ZBteJ/m44tPHqkySJluJkdCCfGgpSH2pbUJ+YO6Ir4CDKDWX4WyW5DcYitmCBXuOLM4iQUpwEhHCp/msfaV9Dj9q40zekdE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776829042; c=relaxed/simple; bh=G7AWuS0ukX1iLsuT9JRXb50DmeYwXhl5ye+VH4MAchk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aMiQZH5of3f8dE+yMHGX4yagCzlKvE/CblSx8Q6RkbxpydCXpPhjdFJnYvNULdr8DmEiugi6Z1eNvc7+hUWtqPnJN1EvZKQP9B/Skp1aYa/gqnw6oA7ink+92BZ7ws4IYLlYtcgrsZrrmhm4Hh+iUgf0E0xLU00S2fcFI2Gcr50= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=B1bngkr5; arc=none smtp.client-ip=209.85.210.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="B1bngkr5" Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-82cf636dac8so2103849b3a.3 for ; Tue, 21 Apr 2026 20:37:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1776829041; x=1777433841; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=YWN2JZ+naXQZkXRKjOmRteQ2UzIkItmXJUEjeeSbwOE=; b=B1bngkr5pCaCurkfF5WO6KnP8WgfLibqPTALjOkhkTLPVQjJ16VILPNJPMG1qbDYvc 09vsw87uFsQVjd9sR5TzPe1+25ucArCCL18QB1GC0+FuFXAorDeZQB2T7D+HaywLxJN2 mJo+/cow9UrDQjfhjqq0AEBzkYlK8r0sjoR+2Er6C4pWlYxgl3CSApMJFRaWFuwtWvuw W5ztJS9gxZK6DbWDLqBGKx8tuu81s//6wiqZaWxnOmb33Xohraxczj+uxep3S5caYoZr 9le36gZu6ho9hD2/kgQ/JRdKvgNrZsxY8q9XJ9ZFKyOas1A6yRjD6N4csCI4Z2bL4csy jJWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776829041; x=1777433841; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=YWN2JZ+naXQZkXRKjOmRteQ2UzIkItmXJUEjeeSbwOE=; b=A3KlcFdW93LZoBNWBgqap6a3mkrzgsXtkY03U6QRBsXcBg7uHChqKgHMtamiIcGzYt Tu4h8R4X8oaBknywZbJEkOfQiUhWoQcpLxZQVTJEvM0QkRFy8t0Cgha6JCg36VyPoNIo i6yqzMcTQbCG0e+ew2EEBv1JpitlR9b5d1z6n7X731tgsoXr66OZSeeyNYdL6/Vt0ITA jUeHFXp0J09hcKnR6FqYDTxoH1cuEXVzR5AJYplE5rask8CjZRbKS8dXXuQ/Att0e8bf XXgNzF/iwS/xzLqhd2PcQq1xpzn3pgy5xEPx3BwWssuot4YPUU8TTco4CP7jVny+K7y8 ABRg== X-Forwarded-Encrypted: i=1; AFNElJ9biKZLFITf75rXYOReM5BLZmLQDw5IJ8XD08KRw4Fp2e7eaohIkovC6tsNrklmjN3uHt3IrdY=@vger.kernel.org X-Gm-Message-State: AOJu0YxRJLNoXogkQhxSWHHy4UeDaDP0Ab50ewiGCgXYcpmjW/K1pPi+ s7/bbVGAG28+aUDuhM+EkOYUHUcimgjRTOkkV4MqHdxjjujCJHHqElLy X-Gm-Gg: AeBDiet8ei2Ne9Ts6EKFc+7FcxnYETVlgcAAJb3Pv4Lh4ghiZv3IMmVyJDF3mDXxteC tI8hFJQAjriJGUC0ELeeG1FJ9KcDxLisxbc/+WYIFHHoYf2UMwHim8aO58kHIyfpb59EzPRXft2 9w/OIQ9MEackIjtqzdwh1jDFDnI3NKN2I1ZYaIEVI4aondgWQ/daWNN3SBn6iHzfA2RLBaEQlqt HeHD+oc0Jw34KKrObf4C9laAqmx98PjFIU1h9oTy6mhAqJaD3KqrioyrBRJeq3K7QXCPLTUfduU EH3Hi2kWpUgS0L4eHlaClLU25ezA8OBVuoXg5+iB4DvrZKZ5UE2wYBIeuqDFAi0r2HVjrAuB52t VmjO6/w8aOEXPJGWbmxHTL6vI3i+EeuQsvbckie71FiQ49OF+Mb0678+kUqKxKJubDn5jByzPTv 9XcGnNL66iTFLgjX3lzVEX2x61VqjIcYE+dNpIHYVRh7HAVBeXMv48+6MjSFUqr1mRabkXzhesF oCygS7r X-Received: by 2002:a05:6a00:4512:b0:82c:e1a0:3453 with SMTP id d2e1a72fcca58-82f8c8fc39amr20671254b3a.26.1776829041112; Tue, 21 Apr 2026 20:37:21 -0700 (PDT) Received: from KERNELXING-MB0.tencent.com ([43.132.141.25]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f8e981c07sm18355473b3a.1.2026.04.21.20.37.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Apr 2026 20:37:20 -0700 (PDT) From: Jason Xing To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, bjorn@kernel.org, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com, sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, Jason Xing Subject: [PATCH net v3 5/8] xsk: avoid skb leak in XDP_TX_METADATA case Date: Wed, 22 Apr 2026 11:36:47 +0800 Message-Id: <20260422033650.68457-6-kerneljasonxing@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20260422033650.68457-1-kerneljasonxing@gmail.com> References: <20260422033650.68457-1-kerneljasonxing@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jason Xing Fix it by explicitly adding kfree_skb() before returning back to its caller. How to reproduce it in virtio_net: 1. the current skb is the first one (which means no frag and xs->skb is NULL) and users enable metadata feature. 2. xsk_skb_metadata() returns a error code. 3. the caller xsk_build_skb() clears skb by using 'skb = NULL;'. 4. there is no chance to free this skb anymore. Closes: https://lore.kernel.org/all/20260415085204.3F87AC19424@smtp.kernel.org/ Fixes: 30c3055f9c0d ("xsk: wrap generic metadata handling onto separate function") Signed-off-by: Jason Xing --- net/xdp/xsk.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 88ec6d2cbbcf..c49b58199d2f 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -741,8 +741,10 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, skb_reserve(skb, hr); if (desc->options & XDP_TX_METADATA) { err = xsk_skb_metadata(skb, buffer, desc, pool, hr); - if (unlikely(err)) + if (unlikely(err)) { + kfree_skb(skb); return ERR_PTR(err); + } } } else { struct xsk_addrs *xsk_addr; -- 2.41.3