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 453D6328610; Tue, 16 Jun 2026 17:04:16 +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=1781629457; cv=none; b=huwsgLzPpM8Dq/xsltr4TFKXZSBTBcdtiNZACdWAbhzleQoghoB18uUdBXDW4sRjGEfq3+BWINpxuUyaQEKfAk9JcVl+XJ7mVti4ic1W+Tu8k/hJO6LAiyJuRgLzMaICCJtVdXdZxxaI3/1C8l3ZW/KqK6mr+GwVIBhv1hJnJ2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629457; c=relaxed/simple; bh=aBcrkcrI50LjRJ9hDBNzW7s2q/xeA8d3bOvXNJbkzvg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y/D0583q0V8MTRtiLZUnGF04ffmcipFCH54lF0Kg0n5wvaRjbiBmUN34TK3lLX0xxd0rbmzamUpx9KnmBqwlz179Rj2sFV3vgecyzAUHMlfNWObHOS7nYJ9GKlgeHxL73nwVaW7MzJBzsOCx2fbCuW77dPGJ6dbBvXLKBAKCUG8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Mj3arHWr; 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="Mj3arHWr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49DF61F000E9; Tue, 16 Jun 2026 17:04:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629456; bh=8W5MS2Dx2DPQvUUa1Y24OY1k4krIs/RlIece/AYY8xI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Mj3arHWr75VFMf7MytjQiiMIRokv4lmCKvefI+amTyqC7GyOKs3szBXeT65H6MV0o QdfdOlc7F56UDii08WkB6gXh/BqMIJIrJihRbhjt577MP13E4JgsZU5sgLmhiSrrvP icYZ+QcvofqiNg5z9zT5KFZuSoJRAX+0Xk0gTc5Y= 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 6.6 255/452] tap: free page on error paths in tap_get_user_xdp() Date: Tue, 16 Jun 2026 20:28:02 +0530 Message-ID: <20260616145131.035960839@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@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 6.6-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 2c4f9d19827f38..5f01c875e49ee4 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1178,6 +1178,7 @@ 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; } @@ -1187,6 +1188,7 @@ 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