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 4232F34B1A6; Tue, 21 Jul 2026 21:46:26 +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=1784670387; cv=none; b=hhJv+aHeETvaMQzVjUtimK20SuP3jHFyyoY63BCP7/2RJS5/svZSQV5RJPzZQgqqK7SP4TFxC+kgip8Km7GtTpRhxH5yy3EHEPCwVihodd63j5Pv5bRrUbPX70nj975RZ5mowhyhLTyg4++d48yAfkXYw9mW1DYU1bcKyVkFdP0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784670387; c=relaxed/simple; bh=NUOLCz2UF2jP5fvuRF6DWe/xRCVFVeYIUuBzgR5J8To=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BQa7O8ZbDw+qI2hEVCJtfp7UPLsm6yEQMtOJNm/7c2vL8eGVsMurEYShkCPGg9ugNay1Iqt357YvUaw6EkkyAeSRZTK/LqJPI1iCv7JrvdTq+gF7DwfA/kDischBZxB4vsnVorTBULMEX8rbkMo8A+1NYxVEE63hOUlXJWcafjs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jz4aFftm; 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="jz4aFftm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A75CC1F000E9; Tue, 21 Jul 2026 21:46:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784670386; bh=ercSN6hfkViG0PcqMRhQqBA2UHNbdycatiCwvCEcLqc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jz4aFftmMi63OZQmDBPNii/OosYWHi7akyCA2Ii32pCpvwE/mfw26h/YDQZx1HTPl oWop3K8mj+XsYYEAeqq4B4I9j8Jb6GEPt41Pz5qTc6tEpZzEsRlXxZ7gaTDm0Jh1Uj xaVmYQywEV0tjUwJs0TBfoEdW69hGlwHt2wq3NIA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daehyeon Ko <4ncienth@gmail.com>, Sabrina Dubroca , Paolo Abeni Subject: [PATCH 6.1 0913/1067] macsec: dont read an unset MAC header in macsec_encrypt() Date: Tue, 21 Jul 2026 17:25:14 +0200 Message-ID: <20260721152444.959745542@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> commit f5089008f90c0a7c5520dff3934e0af00adf322d upstream. macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG. On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header(). On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose. Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver") Cc: stable@vger.kernel.org Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20260703083634.2035145-1-4ncienth@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- drivers/net/macsec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -644,7 +644,7 @@ static struct sk_buff *macsec_encrypt(st } unprotected_len = skb->len; - eth = eth_hdr(skb); + eth = skb_eth_hdr(skb); sci_present = macsec_send_sci(secy); hh = skb_push(skb, macsec_extra_len(sci_present)); memmove(hh, eth, 2 * ETH_ALEN);