Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Anatoly Trosinenko <anatoly.trosinenko@gmail.com>,
        Phillip Lougher <phillip.lougher@gmail.com>, stable@kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 4.4 117/124] squashfs: more metadata hardening
Date:   Sat,  4 Aug 2018 11:01:46 +0200
Message-Id: <20180804082706.835024653@linuxfoundation.org>
In-Reply-To: <20180804082702.434482435@linuxfoundation.org>
References: <20180804082702.434482435@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Linus Torvalds <torvalds@linux-foundation.org>

commit d512584780d3e6a7cacb2f482834849453d444a1 upstream.

Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.

This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Acked-by: Phillip Lougher <phillip.lougher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/squashfs/block.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -166,6 +166,8 @@ int squashfs_read_data(struct super_bloc
 	}
 
 	if (compressed) {
+		if (!msblk->stream)
+			goto read_failure;
 		length = squashfs_decompress(msblk, bh, b, offset, length,
 			output);
 		if (length < 0)