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 8F8A935292A; Tue, 16 Jun 2026 18:19:29 +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=1781633970; cv=none; b=YMlAr70ZlxoEXHeYTy4AImiyz9ARnV+x7jexQIr7LQlLVm7KlWsGFM6racAsNvBCBE+MFUf16gc3nWlnjIIRNYlRbxnbo923IaBq9YUmX4eyuD2N5MSEyZUtAkdPVln9dla9tzf044ga862Pyyw8dELlP1LXlneSKNI9FW/nkiw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781633970; c=relaxed/simple; bh=wwRV8p461imdW1w306IjmqXg5IrwFKLKOf4wAh66DnE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C//7mlZpXJQt0OLhci8Fvl21DpZVejybaVkpRhSaWXUia3/NkWNOBC+9eRBZ7q6kVhh/vjVdJMazHbjTEIxvrgtee0oWRHgdXvUjOzRfF4rsFc3lOOKVDVVyD+cdLse/URkMHOQYTbwjYMEhqg6X+Fs/gCrOZiW7eyQDzzXdgzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fkzrh5j2; 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="fkzrh5j2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 756841F000E9; Tue, 16 Jun 2026 18:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781633969; bh=9teiSd6F75jgX7+fQdh4JVNwXFr3J1rYG8Kn34HuVKY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fkzrh5j2Fr6ie/OW7/2WgwotKwQiP+caihYRNycxXOG8bid8d5aB0EIhhA+veEP7v 9zAiV/K1+sdBNdpjM9Y/qp0u+7jKeihS1q1AzGCt09JWS4Efskf09YRhqBXA907sMO m5Evsln94KSPJiFusZoBafXDNEIvBJ7fdNrpZOhQ= 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 5.15 177/411] tap: free page on error paths in tap_get_user_xdp() Date: Tue, 16 Jun 2026 20:26:55 +0530 Message-ID: <20260616145110.080425920@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@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 5.15-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 a08adca412b41a..3a91972485cc36 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -1143,6 +1143,7 @@ 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; } @@ -1152,6 +1153,7 @@ 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