From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 338041D0975; Wed, 2 Oct 2024 14:27:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727879256; cv=none; b=iuMjQsMR7HzgQJXAe7RGbEVa+L2Qg+hT9hkr0ykq7qz44tE6FpgTd1QxOHXm1iW6VczzIJafx7IPFiIZHWbBDy2byO8vpTDAdOU+H9yOCgZQRayE8IA6yTJS6FJDN0O4xAxrBK02/jfcZEyjFqknbe2jAzabv0SBdjHCJiwPEtU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727879256; c=relaxed/simple; bh=eZWOWWnUE2EMih2UjYo5Q+v8XhSAplr+8E156s4ZQz8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SZJTJEauBNb/u3xa0xm75cKyA+A0rue0oPAVKEU8vkvWLRmgJ4e0ZmFp7lZoajJrBieA7MHqHHU1F7yIsJu1pMWMc3zi98737aGld5PaTV0hV0fTOPcpHnL9u3KBamv4ScrCtZ4JfwrTzrhluHT0o38nX4ZNENeQH9H4OVeZj2w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FIvBNSA8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FIvBNSA8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8F82C4CED5; Wed, 2 Oct 2024 14:27:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727879256; bh=eZWOWWnUE2EMih2UjYo5Q+v8XhSAplr+8E156s4ZQz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FIvBNSA8MihsQbJLUcZtbU7H755Zy28lEGUroTijb39yVhgOe7xwM4D8H1iEsdiE4 wf7ipT2MmHGGm63AA5/XPJlXu4eDz8P69MWur4HdmMA6ju0gm4mao+6ZM9NWA3xZoS r1TKL66NW50VekJBb8zQTLurRylfPz6GnwxTrExw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dmitry Antipov , Kees Cook , Johannes Berg , Sasha Levin Subject: [PATCH 6.6 055/538] wifi: cfg80211: fix UBSAN noise in cfg80211_wext_siwscan() Date: Wed, 2 Oct 2024 14:54:54 +0200 Message-ID: <20241002125754.373721825@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125751.964700919@linuxfoundation.org> References: <20241002125751.964700919@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Antipov [ Upstream commit a26a5107bc52922cf5f67361e307ad66547b51c7 ] Looking at https://syzkaller.appspot.com/bug?extid=1a3986bbd3169c307819 and running reproducer with CONFIG_UBSAN_BOUNDS, I've noticed the following: [ T4985] UBSAN: array-index-out-of-bounds in net/wireless/scan.c:3479:25 [ T4985] index 164 is out of range for type 'struct ieee80211_channel *[]' <...skipped...> [ T4985] Call Trace: [ T4985] [ T4985] dump_stack_lvl+0x1c2/0x2a0 [ T4985] ? __pfx_dump_stack_lvl+0x10/0x10 [ T4985] ? __pfx__printk+0x10/0x10 [ T4985] __ubsan_handle_out_of_bounds+0x127/0x150 [ T4985] cfg80211_wext_siwscan+0x11a4/0x1260 <...the rest is not too useful...> Even if we do 'creq->n_channels = n_channels' before 'creq->ssids = (void *)&creq->channels[n_channels]', UBSAN treats the latter as off-by-one error. Fix this by using pointer arithmetic rather than an expression with explicit array indexing and use convenient 'struct_size()' to simplify the math here and in 'kzalloc()' above. Fixes: 5ba63533bbf6 ("cfg80211: fix alignment problem in scan request") Signed-off-by: Dmitry Antipov Reviewed-by: Kees Cook Link: https://patch.msgid.link/20240905150400.126386-1-dmantipov@yandex.ru [fix coding style for multi-line calculation] Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/wireless/scan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 4d88e797ae49f..4fc6279750ea1 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -3209,8 +3209,8 @@ int cfg80211_wext_siwscan(struct net_device *dev, n_channels = ieee80211_get_num_supported_channels(wiphy); } - creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + - n_channels * sizeof(void *), + creq = kzalloc(struct_size(creq, channels, n_channels) + + sizeof(struct cfg80211_ssid), GFP_ATOMIC); if (!creq) return -ENOMEM; @@ -3218,7 +3218,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, creq->wiphy = wiphy; creq->wdev = dev->ieee80211_ptr; /* SSIDs come after channels */ - creq->ssids = (void *)&creq->channels[n_channels]; + creq->ssids = (void *)creq + struct_size(creq, channels, n_channels); creq->n_channels = n_channels; creq->n_ssids = 1; creq->scan_start = jiffies; -- 2.43.0