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 B2B331DE8AE; Sun, 7 Jun 2026 10:08:20 +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=1780826901; cv=none; b=l8Z0U2zvTgLZuRYut8VSj+Znx+bLcsa5IsPmf8Z78BXGdwgVy/p98wjCyZkpC/Jx7GU8+xTeb51w6aeAECVko6NbXAHK/WbMyBBis/y8Q6NDc1UQy5fGDso6h/UlSWNY+m09XNcN2/iyrNTSJoPG9NgxRfELwiRAhcKhp+TgpvQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780826901; c=relaxed/simple; bh=dthdD0YVtdznP9G7nZ3hAKPdS+oNOp/8BUoE1LrJka8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JFdNM3iQgCEcOh75jeL0Fn094LshFwCWfZ9W+OZ04DtBo8wz/N05VxsPFk6rH/yNq0wnH80ccjA3DTx4w58TTZ4NAxvMH4c3XUksqaCM3lgeEnRYw5Fx6/TKLcWnp9C4O3JAa2ARhCTCJ5ZqCCpvdhRYImN+GRXsTSAAffvv+2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cn8PJoTZ; 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="cn8PJoTZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEBC11F00893; Sun, 7 Jun 2026 10:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780826900; bh=6wxvKocIRDQujnBE/8Dj7Y776HbLph+kHlyQmSeW7ko=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cn8PJoTZio7drpwozVwexy6RywmZFxOKVpDqpZeTig6Q0nBgCwZBoIYTsvbiRE0HI 3IqGtPtoEadHWwSDzYh7WPOzQuOy9gre9D5YhiNCzhjbaripwzCxxf1FUpzIdhwreo L5Qz5lYqHO4JquB/QkO0pDEPq60Q0zJYBGotYEHE= 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 , Sasha Levin Subject: [PATCH 6.18 021/315] tun: free page on build_skb failure in tun_xdp_one() Date: Sun, 7 Jun 2026 11:56:48 +0200 Message-ID: <20260607095728.271355546@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.528828913@linuxfoundation.org> References: <20260607095727.528828913@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 aa8963fdce667a42fb7f0bdd2909fadcab02f9a8 ] When build_skb() fails in tun_xdp_one(), the function sets ret to -ENOMEM and jumps to the out label, which returns without freeing the page that vhost_net_build_xdp() allocated for the frame. As with the short-frame rejection path, tun_sendmsg() discards the per-buffer error and still returns total_len, so vhost_tx_batch() takes the success path and never frees the page. Each build_skb() failure in a batch leaks one page-frag chunk. Free the page before taking the error path, matching the put_page() the other error exits of tun_xdp_one() already perform. Fixes: 043d222f93ab ("tuntap: accept an array of XDP buffs through sendmsg()") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: Dongli Zhang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260521163312.1479805-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index afba37965ce3b7..9a767da38c71e7 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2437,6 +2437,7 @@ static int tun_xdp_one(struct tun_struct *tun, build: skb = build_skb(xdp->data_hard_start, buflen); if (!skb) { + put_page(virt_to_head_page(xdp->data)); ret = -ENOMEM; goto out; } -- 2.53.0