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 A7E06258EDA; Sat, 30 May 2026 18:15:08 +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=1780164909; cv=none; b=Z/cQuy1Ali50ETon7PqidgRJXeCIhDRWArJfWniLQMEOnCt6eRX9i8Uybtv3MdTQJNm3iOorJNFU/50W3ej6VjmUa1WiZeG0GlNYsoDqIMmfUr43HmvHIBN3dIwT2VgOPbtVtOxJjnysVQIJ2i3GUAzCwMVo/GIfVh5bw7PgQbQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780164909; c=relaxed/simple; bh=IQk/brV4TYJQ1K/YX00p4nhGuysPkZoXqBGnaVXKAxY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pRIHZ3WhJCZENuBt31oU9kDRQ5DFe0HWq+mL+Xkxd7CTLkV8yF1A2H2BhDDixUTjsnW8msMFOSV8bZUfQDYHG3N1YMjEFddjgToqmeqj6M0yUN/MIWdVyPiz+5JkMJ3+1R6FjAhDmBXmI1Gz6Z10PW+Iy8Kx6FR9jvTYiQfX0jI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WlubRIT1; 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="WlubRIT1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA9161F00893; Sat, 30 May 2026 18:15:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780164908; bh=FKkkbApDOmjoipnu+8JiHnDCVqLN7ecaeO7NX1ia6rA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WlubRIT1szWHU/WypoiJ8lHTp1o+yzkazKjZ54EN1ZB7cqrAdKXaqac0g+rCLReKE 4uRePVNwQ1egDbnO9LXgtYKnQ7rlSScJBZDhq+0sVmIeHLm8WunBxBlmjRtuEFy/Xm 7HdeUTkDdfjRsjAF/9YrVoSBkCoyz1pjRe/+RhsE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, John Walker , Johannes Berg Subject: [PATCH 5.15 695/776] wifi: cfg80211: advance loop vars in cfg80211_merge_profile() Date: Sat, 30 May 2026 18:06:49 +0200 Message-ID: <20260530160257.798109378@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@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 5.15-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 @@ -2180,6 +2180,9 @@ 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;