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 70EE32459D1; Thu, 28 May 2026 20:18:55 +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=1779999536; cv=none; b=lcInFanyvH72kb2MYYrxr+ZdFIqwIWpqpTlqkfUSE9BTkHpYG7k87iRgaqAkrGzzl4rqxYYY1nYvspTA6pbKZSR1/VQAFd6/hLHXZn4Q1Mqf9n8oVZALiu2VD2UyIxEkK863HX3xYJ/A69XEdZcTopDh9p10ejbVohwG5pCtgZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999536; c=relaxed/simple; bh=VckCvPMsq9zQPuqF/ekSP0UfOcJegDmAGTdLCs9A19s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IEGbetWmCe0VoatbYOuNMAF6wh8GxPpmPhKitqoRWuDgHlp8w5GpjaZQBG2f55zrcxq9MjIiGNHxCuRE/j7YICpUh3gX+nFbd+Z43GlC5a6Hk4ThWwJwzMUD+TmfMWxY+7sKRXaWpVReMSlF9xpCjCakiz072a0ONq/T+tYFx2o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TEB8lWEH; 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="TEB8lWEH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF0E51F000E9; Thu, 28 May 2026 20:18:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779999535; bh=eaOfgvbuguidas5TZc0DjCZ54bWUIskB1LraHMAeOto=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TEB8lWEHT93urNU81s6vofUijVfwM/AXhOME7ucs1EXjftp2HoMbWR8ZLQPYPsldT en6R+MkdM0am2DLSNygNPOeXZaeUhhn+bJL6m1wArHkHWQQsBaNStQA6Jn9hL2V2Lj GDDXWvTedZNrfSCe/xBIMk+qYDOgmho7N5m6YaGA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, John Walker , Johannes Berg Subject: [PATCH 6.18 101/377] wifi: cfg80211: advance loop vars in cfg80211_merge_profile() Date: Thu, 28 May 2026 21:45:39 +0200 Message-ID: <20260528194641.274331277@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194638.371537336@linuxfoundation.org> References: <20260528194638.371537336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Walker commit 7666dbb1bacc4ba522b96740cba7283d243d16e1 upstream. cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS profile that has been split across multiple consecutive MBSSID elements. Its while-loop calls cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem) but never advances mbssid_elem or sub_elem inside the body. Each iteration therefore searches for a continuation that follows the same fixed pair; the helper returns the same next_mbssid; and the same next_sub bytes are memcpy()'d into merged_ie at a growing offset until the buffer fills. Advance both mbssid_elem and sub_elem to the just-consumed continuation so the next call to cfg80211_get_profile_continuation() searches for a further continuation beyond it (or returns NULL when none exists). A specially-crafted malicious beacon can take advantage of this bug to cause the kernel to spend an excessive amount of time in cfg80211_merge_profile (up to as much as 2ms per beacon received), which could theoretically be abused in some way. Cc: stable@vger.kernel.org Fixes: fe806e4992c9 ("cfg80211: support profile split between elements") Signed-off-by: John Walker Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/wireless/scan.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2475,6 +2475,9 @@ size_t cfg80211_merge_profile(const u8 * memcpy(merged_ie + copied_len, next_sub->data, next_sub->datalen); copied_len += next_sub->datalen; + + mbssid_elem = next_mbssid; + sub_elem = next_sub; } return copied_len;