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 00E021DE3B8; Wed, 6 Nov 2024 12:08:05 +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=1730894886; cv=none; b=fz0AgrKJD+Gwo1HbKnCatzVYe3EUkaxvJaxbbYBQIBGO1kaDpAd/usadc0VQTM6Bh+ICw6Be8DH58PrwAQlXWy6YKo3gESQeEIJu58EE6xYshkA+xSVdrwK46BSvvkeWtEKpMguhP/V77qH+KqrHWRZiR6uu8J4VHKIICZY7ZDE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730894886; c=relaxed/simple; bh=bCtFF9KB0IJOS/sIJdEJIQYUcT416mFGU7TIODj/DwQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U4gNIgIEXmO5SzjQ31dD2SLwELVHUiGREWQysqROzza4G27VIrSuskFBXW2w/JJgHZlBrlq2mr+OxT9bmN3nfx+/VisZ4zNakl42d+vR/G03JEiz8fmOuqFE4BhR3m8GK5QGMXVWbsBhPAr7kLHy8hpHmPL+E0sSmUpTFzByLkQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LrcUC/ET; 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="LrcUC/ET" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B8DAC4CECD; Wed, 6 Nov 2024 12:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730894885; bh=bCtFF9KB0IJOS/sIJdEJIQYUcT416mFGU7TIODj/DwQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LrcUC/ETaobQoaXLKn0yS36H5p11ibePJyMnFtywpIQS/s3Vj7b7Dk59V+nIVPQ70 /NHbxWkBmv8P8W56Kp6OYYaX99sIDO/l8e/P4+f3QEWiu011EPw2ds6qRIXV2A7RTs ZdrX4hHVrAde+cdVojFxdyYIaX3PBPQusFaJP0a8= 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 4.19 032/350] wifi: cfg80211: fix UBSAN noise in cfg80211_wext_siwscan() Date: Wed, 6 Nov 2024 12:59:20 +0100 Message-ID: <20241106120321.674708970@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120320.865793091@linuxfoundation.org> References: <20241106120320.865793091@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-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 0dc27703443c8..4c6c333011e02 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1414,8 +1414,8 @@ 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) { err = -ENOMEM; @@ -1425,7 +1425,7 @@ 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