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 6937A3876CF; Tue, 16 Jun 2026 16:49:49 +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=1781628590; cv=none; b=rl5M+M07OUjL++abu6cGNmVaNw0r2b0cLtBdRVVsfiCask8vfJ0Rxs9DB8BW3k1zPocgcLkxDBfxxlzL6G7Tuhf9+14XDRKMroejcuXtcmF7iGnxpF+pc4jmIVOvJm6bK+eu2vo51yI7uxTBiTSP11Jj6O810uB+WX9eIfuX//Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781628590; c=relaxed/simple; bh=OJvROmWuHygzPkwczYGF2+90eyDwvqDrAHtCUlweGDc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mDdsLa1AlP1MmddrBwdhMCT1dgl0S0ysRt7X0YxY7aqaIgekmukLZsrVWJKmlcjwV6yMWvjwndhFiD0LKN6VB+KVLDOxb0M8NO+5W3ChaM2OMcapttIEm29FVKgPiqkj2/lwUmRVT2rKWw7ClYUI8syLc7MC6vFjaM1mwKblDHo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dWnyQmuo; 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="dWnyQmuo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E24B1F000E9; Tue, 16 Jun 2026 16:49:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781628589; bh=9SUuFkbQdvtpeDh1k3CRGtSwHuIapV3xInG+Oau+IjA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dWnyQmuoEcugMQsW1YEoL2clF2Sqb+RqTss/2SncqdGn6FVnWc4Ts66RsCwOEBlcE WRVKnUwGBVwpuRSp2k4dXiJTgK6PZ+hJKcixWaqstoBGp6yi6VBDTEOIQ87EL21j4L B66J+I9G5Mr4jazPMv/g1wQtvwHGDZSZkorDIq/A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuhao Jiang , Junrui Luo , Jakub Kicinski Subject: [PATCH 6.6 125/452] macsec: fix replay protection at XPN lower-PN wrap Date: Tue, 16 Jun 2026 20:25:52 +0530 Message-ID: <20260616145124.315387764@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: Junrui Luo commit e68842b3356471ba56c882209f324613dac47f64 upstream. In macsec_post_decrypt(), when pn is U32_MAX, pn + 1 overflows u32 to 0 and the first branch never fires. If next_pn_halves.lower is also in the upper half, pn_same_half(pn, lower) is true and the XPN else-if does not fire either, leaving next_pn_halves unchanged. An attacker that captures the legitimate frame carrying pn == 0xFFFFFFFF on an XPN association can then replay it indefinitely, since lowest_pn never rises above the captured pn and macsec_decrypt() reconstructs the same IV. Extend the XPN else-if to also fire when pn + 1 wraps to 0, so receipt of pn == U32_MAX advances next_pn_halves to (upper + 1, 0). Fixes: a21ecf0e0338 ("macsec: Support XPN frame handling - IEEE 802.1AEbw") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Link: https://patch.msgid.link/SYBPR01MB78813FD49E58F253B989F197AF012@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/macsec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -800,7 +800,8 @@ static bool macsec_post_decrypt(struct s if (pn + 1 > rx_sa->next_pn_halves.lower) { rx_sa->next_pn_halves.lower = pn + 1; } else if (secy->xpn && - !pn_same_half(pn, rx_sa->next_pn_halves.lower)) { + (pn + 1 == 0 || + !pn_same_half(pn, rx_sa->next_pn_halves.lower))) { rx_sa->next_pn_halves.upper++; rx_sa->next_pn_halves.lower = pn + 1; }