From patchwork Wed Jun 12 12:38:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 13694904 X-Patchwork-Delegate: johannes@sipsolutions.net Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 E557C16F29C for ; Wed, 12 Jun 2024 12:38:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718195896; cv=none; b=OLruJahHt4O8CpfBgiuLXZmYFT+PzjaFNCHo2UKegVePY0dfdXAGQvobMP5BSl0smCNKHUfH8ECZKhxKDJhbT88924qrg2iUZ1ALNzCqnxm/oFNek7mI594e4nSA/wy7M25GF7BB+clGT6LaQGTYqkXneX6+fSJ6kT7Ela5sBkE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718195896; c=relaxed/simple; bh=k7CFfyKRu5Cq53ohUFP3M+KVUJJJF7DzWumrspjwV+I=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=VHhAbAIjmyocE68hYOjr5rxMgB91VmcCsz8+vFycuOhx6LAUposPfF6A16+/ttLTzKrV2BS59GrGVufrMRdNMhTGSZJVjmm0lUjqvT+PlDEwY1RayVxLDM3h592mNo+5upZ4JMOTEB7aLq3M8b4G9+GhsYQWpt4SxOfu2CdKNGc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=mRbM0o9I; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="mRbM0o9I" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-To:Resent-Cc: Resent-Message-ID:In-Reply-To:References; bh=tCgEKvw0cPmvBlFtaVhYIHHtQAEVyBLgpngYvIzz5yY=; t=1718195895; x=1719405495; b=mRbM0o9ICR2GWv5a82RgMG+vhO3TJmbRQ85Odz1m7gaticL6Umlt/KA5sImnwScw8HHRr/3Y8Yf OHFX/sSKGnNjTZ3Lzyo2xZWQmK0U8mCKwOp0aNYvFrp4BYd6LQY30qYiz3N/ujnrC/eAok68NmTFz C5SYG0KTH7pFpfHV0tvEfa6JjDDqH3atNeJr25s7LaSdMvG9ok/3KA7YPCTmevuIYUkfrz2tnf1eB AniyYqBXq8jMuhGEMVonHM3Qc0Gl0bwpuM6viGHyjRORFPxHvv1snD/t3EH/DYSflo/riP1CS3Oqo O2TYEbbH26CKNLoFR66qrZ2pVXeDt1NRTaQA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1sHNEy-0000000AH8F-0qts; Wed, 12 Jun 2024 14:38:12 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg , Miriam Rachel Korenblit Subject: [PATCH] wifi: mac80211: check SSID in beacon Date: Wed, 12 Jun 2024 14:38:10 +0200 Message-ID: <20240612143809.8b24a3d26a3d.I3e3ef31dbd2ec606be74d502a9d00dd9514c6885@changeid> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Johannes Berg Check that the SSID in beacons is correct, if it's not hidden and beacon protection is enabled (otherwise there's no value). If it doesn't match, disconnect. Reviewed-by: Miriam Rachel Korenblit Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index ef3280fafbe9..df0978ce69de 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -6654,6 +6654,29 @@ ieee80211_mgd_check_cross_link_csa(struct ieee80211_sub_if_data *sdata, } } +static bool ieee80211_mgd_ssid_mismatch(struct ieee80211_sub_if_data *sdata, + const struct ieee802_11_elems *elems) +{ + struct ieee80211_vif_cfg *cfg = &sdata->vif.cfg; + static u8 zero_ssid[IEEE80211_MAX_SSID_LEN]; + + if (!elems->ssid) + return false; + + /* hidden SSID: zero length */ + if (elems->ssid_len == 0) + return false; + + if (elems->ssid_len != cfg->ssid_len) + return true; + + /* hidden SSID: zeroed out */ + if (memcmp(elems->ssid, zero_ssid, elems->ssid_len)) + return false; + + return memcmp(elems->ssid, cfg->ssid, cfg->ssid_len); +} + static void ieee80211_rx_mgmt_beacon(struct ieee80211_link_data *link, struct ieee80211_hdr *hdr, size_t len, struct ieee80211_rx_status *rx_status) @@ -6795,6 +6818,15 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_link_data *link, elems = ieee802_11_parse_elems_full(&parse_params); if (!elems) return; + + if (rx_status->flag & RX_FLAG_DECRYPTED && + ieee80211_mgd_ssid_mismatch(sdata, elems)) { + sdata_info(sdata, "SSID mismatch for AP %pM, disconnect\n", + sdata->vif.cfg.ap_addr); + __ieee80211_disconnect(sdata); + return; + } + ncrc = elems->crc; if (ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK) &&