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 3E55244B69C; Tue, 16 Jun 2026 15:55:14 +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=1781625315; cv=none; b=nm8y8AJgsVphvuWPcOnsiSBGWw595g0qQSRVkeakEBXBT1PZ5odbelxym5YOr5D5Ul04shmjl/w54hg31qkldYn0jiFW7NOV8aPOFeRvWa+FT3YHT+nXjsmtu++O2XfMqsvC2rX/mk9LqdysqDW1/ISHRMuOVJhMeLf7MT8E1iM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781625315; c=relaxed/simple; bh=JApOTiSChiXd9+LuzNxRZkhOKw+T7i1IkyavjwnMsf4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RmzG5yb/l90HmHAM9YtIPbUuK0WBzTX6pYyr+084p/UEkFepj41Xn4MrChVhCGymUYgR0+MIk1pCQnRBkW1s5Rymc8WX7aEuNMCJ/wzgf6hov9jH3F71H5b0EGLjv54Z6EB69Dk+Eqpc5YM+y4RyhevELJVBVbpAXmxR+RMRstQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=12AgqLcM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="12AgqLcM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254101F000E9; Tue, 16 Jun 2026 15:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781625314; bh=5HvcDoyVLCLTA2Jq55dN2pT3pQzM3mOL2ME26TkgF6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=12AgqLcMjOBmN+YfUnzMkyNKpsXoaWf5PdbYzrSsSKBkrXlLW/9kWtPqgEKFmQHD5 WHjWAp6uS96xY0BxbybI5BtXtrjJiCYdUBI6yDMkBrzsGDuxhs66laNUsZd/6hdit0 xW2MpszHsLg2QFwT5n+oNk5aUSCRb9ReyKLeSDns= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , Dongli Zhang , Willem de Bruijn , Jakub Kicinski , Harshit Mogalapalli , Sasha Levin Subject: [PATCH 6.18 085/325] tap: free page on error paths in tap_get_user_xdp() Date: Tue, 16 Jun 2026 20:28:01 +0530 Message-ID: <20260616145101.951716546@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145057.827196531@linuxfoundation.org> References: <20260616145057.827196531@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit 3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2 ] tap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL, and returns -ENOMEM when build_skb() fails. Both paths jump to the err label without freeing the page that vhost_net_build_xdp() allocated for the frame. tap_sendmsg() discards the per-buffer return value and always returns 0, so vhost_tx_batch() takes the success path and never frees the page; each rejected frame in a batch leaks one page-frag chunk. Free the page on both error paths, before the skb is built. This is the tap counterpart of the same leak in tun_xdp_one(). Fixes: 0efac27791ee ("tap: accept an array of XDP buffs through sendmsg()") Fixes: ed7f2afdd0e0 ("tap: add missing verification for short frame") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: Dongli Zhang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260521163230.1478627-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski (cherry picked from commit 3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2) Signed-off-by: Harshit Mogalapalli Signed-off-by: Sasha Levin --- drivers/net/tap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 6fd3b14273b374..b51ce7af1b20f9 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1052,6 +1052,7 @@ static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp) int err, depth; if (unlikely(xdp->data_end - xdp->data < ETH_HLEN)) { + put_page(virt_to_head_page(xdp->data)); err = -EINVAL; goto err; } @@ -1061,6 +1062,7 @@ static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp) skb = build_skb(xdp->data_hard_start, buflen); if (!skb) { + put_page(virt_to_head_page(xdp->data)); err = -ENOMEM; goto err; } -- 2.53.0