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 84BB5511E8F; Mon, 31 Aug 2026 13:43:02 +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=1788183784; cv=none; b=H+1Z4GMzW00T7SNdr0ivHvVgg3vChgos3D2niXpw/xPQ6HoO2TvsdZKyfNZ826CdVanj2/uGlShg9bYupnviJt6Va+2+baQzbB5Oz7VpQZy/ebi6j8C03iLKui4d4mvMnvu3dVAhP3QXnQF8TJN9vJiL3ROOt7CStFZfoHegPvg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788183784; c=relaxed/simple; bh=4lSmKx7Az8BuFzr1SOZErnp2DA8BTtaf14Yi+04W1es=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C1CxzpRjTnFqOhBZxp1IlzGu+bKGZnYTTnA42CxTOsa7mUrMxzv8ju4nPCHeOCGr6vnzqG8znKaOUtYdNsTpi+R/DKrBfXfFg8g104ng7rVigE+L3D3+QPNjXYh+52nk1i/oMbrG3G15hgjjxCiUTYGhXGicjgBKjf5kcKJ5rj0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=c9z0xVN7; 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="c9z0xVN7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06C221F00A3D; Mon, 31 Aug 2026 13:43:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788183782; bh=5fAP+drLXHdu17teRaYHEZUQ4jlD9ts5h7yeDKyu6RM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=c9z0xVN7KkgJHYiZ4ZrxMJnoWBc1ZPXfe3t7ZyzPRHc0/yS8RabddfN08l3mOYuD/ OVQ3NXFooIERgFJYs50vLqfaaYaKn5o4gx+9Xa3uhnddlRm4t7vXzFTqfq1K0LsAWB D7rwn2JsUPwJZgZK3Yz1E3kTgHXW3crEZF2g7/bw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, zdi-disclosures@trendmicro.com, Sabrina Dubroca , Breno Leitao , Steffen Klassert Subject: [PATCH 7.1 40/76] xfrm: espintcp: fix UAF during close Date: Mon, 31 Aug 2026 15:34:12 +0200 Message-ID: <20260831133401.495133877@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.185608553@linuxfoundation.org> References: <20260831133359.185608553@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 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sabrina Dubroca commit deb232e884877bf10b4ce2580909eedec986c284 upstream. ZDI reported and analyzed a race condition during close for espintcp sockets: espintcp_close() frees emsg->skb via kfree_skb() without holding any socket lock. Concurrently, the xfrm_trans_reinject work queue invokes esp_output_tcp_finish() -> espintcp_push_skb() -> espintcp_push_msgs() -> skb_send_sock_locked(), which reads the same skb as a data source. Fix this by adding a synchronize_rcu() call after resetting sk_prot, since esp_output_tcp_finish() runs under RCU and won't use a socket with sk_prot == &tcp_prot. Simply taking the socket lock in espintcp_close() could lead to leaks, if esp_output_tcp_finish() re-adds an skb in the slot we just freed. After this, the existing barrier() is no longer needed. Cc: stable@vger.kernel.org Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: zdi-disclosures@trendmicro.com Signed-off-by: Sabrina Dubroca Reviewed-by: Breno Leitao Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/xfrm/espintcp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/xfrm/espintcp.c +++ b/net/xfrm/espintcp.c @@ -515,7 +515,8 @@ static void espintcp_close(struct sock * strp_stop(&ctx->strp); sk->sk_prot = &tcp_prot; - barrier(); + + synchronize_rcu(); disable_work_sync(&ctx->work); strp_done(&ctx->strp);