From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f173.google.com (mail-pg1-f173.google.com [209.85.215.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D65533FA5F1 for ; Tue, 7 Jul 2026 12:00:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783425603; cv=none; b=HFw93VSKuDOkK6kt10EJX9ywPTz5IXLhVjXCaAlUnyEI9YwjQ/fwLcmjW1vVZKFrKY30/rBz94ggXZSlwpqFFHYy9otIe4l9ln4wAKQl0dplJ6z9nnaMEDXZtnWyl/kfddurCWYjKJuRn/cGGADtIDYJGze5QPPM3vRUZ7FDEwA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783425603; c=relaxed/simple; bh=NH8KzkcpA2UkqkGy4ApP5rltY8b6jpgrZrvEARN4Tgo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ThXq1R+PlmVoxTSBl1fGP40IYT45bs04+reXFMWYoUtjLQwzBINCJquY65DFxQO1JylPG5fmvz9kPeSblBfsmmGiqw5EWz4XEdXtYDasRd3QUNuTHvNtQsLVvo35RVWnDoKpv8FLm9Ldr06CzsYp9ewCKasbHVqqULbGr0DzAPA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=O6brfJq9; arc=none smtp.client-ip=209.85.215.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="O6brfJq9" Received: by mail-pg1-f173.google.com with SMTP id 41be03b00d2f7-c9b373d5af0so3064998a12.2 for ; Tue, 07 Jul 2026 05:00:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783425601; x=1784030401; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=JrdDA/3Tx7GekjGo23iiSAy0AqP4qNw67v0Rs6Rz9B4=; b=O6brfJq9hrxpaP6LxatvKZIXsXc5nTZvc/njRCH1PXdckw7/WhGJK+XQKVZwt1bAr9 vNFUtvjpd1bbixOD2vXldHvxMoHJMQKR7uCafIPxVMpjvNhR0mLml6xh2BUST5umK/96 TWJmsOJ8uCxOFyDVMotA+EsoHdnPlzWNZIx01y0hvlCvBssLxJCQysKseX1fRDQuvqpW tDy+9/T9VgFXckN0h9eosQJ+uKTqH14+nH0aSsh84RaNEh9GR3F1jFFZXTXs/k1untdu VuI9yU++WWiL0YoPl+whmXoCQRZVmNRKu5hJk+WJEyYrJFEQvjF35QZBrx9OfATYJEqt /T2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783425601; x=1784030401; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=JrdDA/3Tx7GekjGo23iiSAy0AqP4qNw67v0Rs6Rz9B4=; b=JFIcEpx1sbmPQyIYX566IuFsNIm+q+VNXpYTc9lbRhRkX+367E0bdtCEDD9usJr0P8 eSazWuvZdNYutxKK2KQW6cVFtILsqmpckFgeBjfam1AQrYxhooj097dBG+fweVbsMo1j +ICu2A00F/qVZSt98KWvQZbfVlO/tEEf5EHvfH1QendXArSFd00lg7Gsc1keYFdyBPGz SWlH64gBcP1X3g6hcJk7DXJBwarwD3Ucl4Zw0C3QpLesoFIPSOXwL2akPtuicxXHf+GC vs4WozdjR9G1uSu95NMDpNVMZ6P6eEQR6U3q7KvuhWv784rb7niv2TUR0ojpsEuFrTWF CUkQ== X-Forwarded-Encrypted: i=1; AHgh+RrnDblyp6RGvMmVCZwHeuZKti1azP8rYgDHGX3HS4JSW+Y4I/amm8WFQn42EA7QjpU1hsSuwQjVycFzkqQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yw9Mm50Lg/hIwTB5gHXikPm0kmKg+1Hxmv6ep92QKHY189tDrkL nkoaN+Xr8/BKPVk7vb2y4l4rAJhmopk8cpa9fMq0EgKZpV/5OzZu6qQR X-Gm-Gg: AfdE7cnES1BjUlDVpTXMuQA26bmJW98Mrffb+E22Tt8U1g5T3mW6PATTJBXrA/qHbDj c8AWANmnf7w3n1zvrNNrY10T1cCtfFHtptD+H9UbXKQNlOa+R4MK9vPkxzMtJKVohMxq7qj7ZIN FvtHJQSLEmVdg3W35U6dTA5H5QQ8tXLgqVEjcl/mSH1O0jLhYbj5d59tunkAzpvMScmac+X9z8g 2P/paCE6WpAnUjGabGHT+sUY2577MR3dAryTbphM3EstP3fHdYG1yFCA9JnZ2XyiFIK+S3iTlLe 4eO5nfn4sMlArm80kBtFuDneZzWHJo5o2Cmt57pf8NcEnxSLq0t0zUlmBi1VsH3HZXvnouZ8rvd v0aOOSET3mBEzY7UXYUgtBMKQ/qdabAF9zoyC41GvFZFiZJt0c/CAEaW96hmsag9HHv8UEkFc8u lMN8YhFabITzDKOQUCNPOGI18BVNqY0JFUFxY8n+HV X-Received: by 2002:a05:6a20:9595:b0:3b4:8717:1c21 with SMTP id adf61e73a8af0-3c08ee5177emr6231987637.35.1783425601156; Tue, 07 Jul 2026 05:00:01 -0700 (PDT) Received: from localhost.localdomain ([192.197.201.174]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-311747f596asm7785716eec.2.2026.07.07.04.59.59 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 07 Jul 2026 05:00:00 -0700 (PDT) From: =?UTF-8?q?HE=20WEI=20=28=E3=82=AE=E3=82=AB=E3=82=AF=29?= To: Johannes Berg Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Sara Sharon , Luca Coelho , =?UTF-8?q?HE=20WEI=20=28=E3=82=AE=E3=82=AB=E3=82=AF=29?= Subject: [PATCH v3] wifi: cfg80211: bound element ID read when checking non-inheritance Date: Tue, 7 Jul 2026 20:59:54 +0900 Message-ID: <20260707115954.21721-1-skyexpoc@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260626144543.5034-1-skyexpoc@gmail.com> References: <20260626144543.5034-1-skyexpoc@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit cfg80211_is_element_inherited() reads the first data octet of the candidate element (id = elem->data[0]) to look it up in an extension non-inheritance list. It does so after testing elem->id, but without verifying that the element actually has a data octet. A zero-length extension element (WLAN_EID_EXTENSION with length 0) therefore makes it read one octet past the end of the element. _ieee802_11_parse_elems_full() runs this check for every element of a frame once a non-inheritance context exists -- e.g. while parsing a per-STA profile of a Multi-Link element in a (re)association response, or a non-transmitted BSS profile -- so a crafted frame from an AP can trigger a one-octet slab-out-of-bounds read during element parsing: BUG: KASAN: slab-out-of-bounds in cfg80211_is_element_inherited Read of size 1 ... in net/wireless/scan.c Return early (treat the element as inherited) when an extension element carries no data, mirroring the existing handling of empty ID lists. The bug was found by fuzzing ieee802_11_parse_elems_full() under KASAN. Fixes: f7dacfb11475 ("cfg80211: support non-inheritance element") Signed-off-by: HE WEI (ギカク) --- Changes in v3: - Move the version changelog below the --- line and trim the Fixes commit id to 12 characters (checkpatch). Changes in v2: - Correct the Fixes tag. The unchecked elem->data[0] read was introduced in 2019 by f7dacfb11475 ("cfg80211: support non-inheritance element") -- the commit that added cfg80211_is_element_inherited() -- not by dfd9aa3e7a45, which only rewrote the sibling cfg80211_gen_new_ie() and never touched this function. net/wireless/scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 05b7dc6b7..0a44856b1 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -205,7 +205,7 @@ bool cfg80211_is_element_inherited(const struct element *elem, return true; if (elem->id == WLAN_EID_EXTENSION) { - if (!ext_id_len) + if (!ext_id_len || !elem->datalen) return true; loop_len = ext_id_len; list = &non_inherit_elem->data[3 + id_len]; -- 2.43.0