[PATCH] Revert "scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()"

From: Andrea Parri (Microsoft)
Date: Fri Dec 11 2020 - 08:15:52 EST


This reverts commit 3b8c72d076c42bf27284cda7b2b2b522810686f8.

Dexuan reported a regression where StorVSC fails to probe a device (and
where, consequently, the VM may fail to boot). The root-cause analysis
led to a long-standing race condition that is exposed by the validation
/commit in question. Let's put the new validation aside until a proper
solution for that race condition is in place.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: linux-scsi@xxxxxxxxxxxxxxx
---
drivers/scsi/storvsc_drv.c | 5 -----
1 file changed, 5 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 99c8ff81de746..ded00a89bfc4e 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1246,11 +1246,6 @@ 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,
--
2.25.1