2020-12-11 14:18:51

by Andrea Parri

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

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) <[email protected]>
Cc: Dexuan Cui <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: [email protected]
---
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


2020-12-11 14:40:28

by Wei Liu

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

On Fri, Dec 11, 2020 at 02:14:04PM +0100, Andrea Parri (Microsoft) wrote:
> 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) <[email protected]>
> Cc: Dexuan Cui <[email protected]>
> Cc: "James E.J. Bottomley" <[email protected]>
> Cc: "Martin K. Petersen" <[email protected]>
> Cc: [email protected]

Hi Martin

Sorry for the last minute patch. We would very like this goes into 5.10
if possible; otherwise Linux 5.10 is going to be broken on Hyper-V. :-(

Wei.

2020-12-11 18:58:23

by Wei Liu

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

On Fri, Dec 11, 2020 at 09:59:34AM -0500, Martin K. Petersen wrote:
>
> Wei,
>
> > Sorry for the last minute patch. We would very like this goes into
> > 5.10 if possible; otherwise Linux 5.10 is going to be broken on
> > Hyper-V. :-(
>
> Applied to 5.10/scsi-fixes.

Thanks Martin.

2020-12-12 13:29:39

by Martin K. Petersen

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


Wei,

> Sorry for the last minute patch. We would very like this goes into
> 5.10 if possible; otherwise Linux 5.10 is going to be broken on
> Hyper-V. :-(

Applied to 5.10/scsi-fixes.

--
Martin K. Petersen Oracle Linux Engineering