Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org,
        Saruhan Karademir <skarade@microsoft.com>,
        Sasha Levin <sashal@kernel.org>, devel@linuxdriverproject.org
Subject: [PATCH AUTOSEL 5.9 15/23] scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()
Date:   Sat, 12 Dec 2020 11:07:56 -0500
Message-Id: <20201212160804.2334982-15-sashal@kernel.org>
In-Reply-To: <20201212160804.2334982-1-sashal@kernel.org>
References: <20201212160804.2334982-1-sashal@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: "Andrea Parri (Microsoft)" <parri.andrea@gmail.com>

[ Upstream commit 3b8c72d076c42bf27284cda7b2b2b522810686f8 ]

Check that the packet is of the expected size at least, don't copy data
past the packet.

Link: https://lore.kernel.org/r/20201118145348.109879-1-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: Saruhan Karademir <skarade@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/storvsc_drv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 8f5f5dc863a4a..6779ee4edfee3 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1246,6 +1246,11 @@ static void storvsc_on_channel_callback(void *context)
 		request = (struct storvsc_cmd_request *)
 			((unsigned long)desc->trans_id);
 
+		if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) - vmscsi_size_delta) {
+			dev_err(&device->device, "Invalid packet len\n");
+			continue;
+		}
+
 		if (request == &stor_device->init_request ||
 		    request == &stor_device->reset_request) {
 			memcpy(&request->vstor_packet, packet,
-- 
2.27.0