* [PATCH] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)
@ 2021-04-16 10:22 Michael Tokarev
2021-04-16 11:27 ` [PATCH-for-6.0?] " Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Michael Tokarev @ 2021-04-16 10:22 UTC (permalink / raw)
To: qemu-devel; +Cc: qemu-trivial, Michael Tokarev, Prasad J Pandit, qemu-stable
During previous attempt to fix CVE-2021-3392 it was discovered
that MPTSASState.pending is actually not used. So instead of
fixing the prob, just remove the offending code entirely
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: Prasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
---
hw/scsi/mptsas.c | 4 ----
hw/scsi/mptsas.h | 1 -
2 files changed, 5 deletions(-)
diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
index 7416e78706..5abbc742aa 100644
--- a/hw/scsi/mptsas.c
+++ b/hw/scsi/mptsas.c
@@ -257,7 +257,6 @@ static void mptsas_free_request(MPTSASRequest *req)
req->sreq->hba_private = NULL;
scsi_req_unref(req->sreq);
req->sreq = NULL;
- QTAILQ_REMOVE(&s->pending, req, next);
}
qemu_sglist_destroy(&req->qsg);
g_free(req);
@@ -303,7 +302,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
}
req = g_new0(MPTSASRequest, 1);
- QTAILQ_INSERT_TAIL(&s->pending, req, next);
req->scsi_io = *scsi_io;
req->dev = s;
@@ -1319,8 +1317,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
- QTAILQ_INIT(&s->pending);
-
scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL);
}
diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
index b85ac1a5fc..c046497db7 100644
--- a/hw/scsi/mptsas.h
+++ b/hw/scsi/mptsas.h
@@ -79,7 +79,6 @@ struct MPTSASState {
uint16_t reply_frame_size;
SCSIBus bus;
- QTAILQ_HEAD(, MPTSASRequest) pending;
};
void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH-for-6.0?] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)
2021-04-16 10:22 [PATCH] mptsas: remove unused MPTSASState.pending (CVE-2021-3392) Michael Tokarev
@ 2021-04-16 11:27 ` Philippe Mathieu-Daudé
2021-04-16 11:33 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-04-16 11:27 UTC (permalink / raw)
To: Michael Tokarev, qemu-devel, Peter Maydell
Cc: qemu-trivial, Prasad J Pandit, qemu-stable
On 4/16/21 12:22 PM, Michael Tokarev wrote:
> During previous attempt to fix CVE-2021-3392 it was discovered
> that MPTSASState.pending is actually not used. So instead of
> fixing the prob, just remove the offending code entirely
What problem?
>
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> Cc: Prasad J Pandit <pjp@fedoraproject.org>
> Cc: qemu-stable@nongnu.org
> ---
> hw/scsi/mptsas.c | 4 ----
> hw/scsi/mptsas.h | 1 -
> 2 files changed, 5 deletions(-)
>
> diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
> index 7416e78706..5abbc742aa 100644
> --- a/hw/scsi/mptsas.c
> +++ b/hw/scsi/mptsas.c
> @@ -257,7 +257,6 @@ static void mptsas_free_request(MPTSASRequest *req)
> req->sreq->hba_private = NULL;
> scsi_req_unref(req->sreq);
> req->sreq = NULL;
> - QTAILQ_REMOVE(&s->pending, req, next);
> }
> qemu_sglist_destroy(&req->qsg);
> g_free(req);
> @@ -303,7 +302,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
> }
>
> req = g_new0(MPTSASRequest, 1);
> - QTAILQ_INSERT_TAIL(&s->pending, req, next);
> req->scsi_io = *scsi_io;
> req->dev = s;
>
> @@ -1319,8 +1317,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
>
> s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
>
> - QTAILQ_INIT(&s->pending);
> -
> scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL);
> }
>
> diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
> index b85ac1a5fc..c046497db7 100644
> --- a/hw/scsi/mptsas.h
> +++ b/hw/scsi/mptsas.h
> @@ -79,7 +79,6 @@ struct MPTSASState {
> uint16_t reply_frame_size;
>
> SCSIBus bus;
> - QTAILQ_HEAD(, MPTSASRequest) pending;
> };
>
> void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH-for-6.0?] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)
2021-04-16 11:27 ` [PATCH-for-6.0?] " Philippe Mathieu-Daudé
@ 2021-04-16 11:33 ` Philippe Mathieu-Daudé
2021-04-18 5:14 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-04-16 11:33 UTC (permalink / raw)
To: Michael Tokarev, qemu-devel, Fam Zheng, Paolo Bonzini
Cc: qemu-trivial, Peter Maydell, Prasad J Pandit, qemu-stable
Cc'ing maintainers.
On 4/16/21 1:27 PM, Philippe Mathieu-Daudé wrote:
> On 4/16/21 12:22 PM, Michael Tokarev wrote:
>> During previous attempt to fix CVE-2021-3392 it was discovered
>> that MPTSASState.pending is actually not used. So instead of
>> fixing the prob, just remove the offending code entirely
>
> What problem?
>
>>
>> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
>> Cc: Prasad J Pandit <pjp@fedoraproject.org>
>> Cc: qemu-stable@nongnu.org
>> ---
>> hw/scsi/mptsas.c | 4 ----
>> hw/scsi/mptsas.h | 1 -
>> 2 files changed, 5 deletions(-)
>>
>> diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
>> index 7416e78706..5abbc742aa 100644
>> --- a/hw/scsi/mptsas.c
>> +++ b/hw/scsi/mptsas.c
>> @@ -257,7 +257,6 @@ static void mptsas_free_request(MPTSASRequest *req)
>> req->sreq->hba_private = NULL;
>> scsi_req_unref(req->sreq);
>> req->sreq = NULL;
>> - QTAILQ_REMOVE(&s->pending, req, next);
>> }
>> qemu_sglist_destroy(&req->qsg);
>> g_free(req);
>> @@ -303,7 +302,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
>> }
>>
>> req = g_new0(MPTSASRequest, 1);
>> - QTAILQ_INSERT_TAIL(&s->pending, req, next);
>> req->scsi_io = *scsi_io;
>> req->dev = s;
>>
>> @@ -1319,8 +1317,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
>>
>> s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
>>
>> - QTAILQ_INIT(&s->pending);
>> -
>> scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL);
>> }
>>
>> diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
>> index b85ac1a5fc..c046497db7 100644
>> --- a/hw/scsi/mptsas.h
>> +++ b/hw/scsi/mptsas.h
>> @@ -79,7 +79,6 @@ struct MPTSASState {
>> uint16_t reply_frame_size;
>>
>> SCSIBus bus;
>> - QTAILQ_HEAD(, MPTSASRequest) pending;
>> };
>>
>> void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);
>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH-for-6.0?] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)
2021-04-16 11:33 ` Philippe Mathieu-Daudé
@ 2021-04-18 5:14 ` Philippe Mathieu-Daudé
2021-04-18 5:16 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-04-18 5:14 UTC (permalink / raw)
To: Michael Tokarev, qemu-devel, Fam Zheng, Paolo Bonzini
Cc: Peter Maydell, Prasad J Pandit, qemu-trivial, Don Slutz,
Li Qiang, qemu-stable
On 4/16/21 1:33 PM, Philippe Mathieu-Daudé wrote:
> Cc'ing maintainers.
>
> On 4/16/21 1:27 PM, Philippe Mathieu-Daudé wrote:
>> On 4/16/21 12:22 PM, Michael Tokarev wrote:
>>> During previous attempt to fix CVE-2021-3392 it was discovered
>>> that MPTSASState.pending is actually not used. So instead of
>>> fixing the prob, just remove the offending code entirely
>>
>> What problem?
Digging a bit I found:
https://bugs.launchpad.net/qemu/+bug/1914236
and Paolo's comment:
https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg02660.html
So your patch now makes sense, but please:
1/ Reword including Prasad description:
"""
While processing SCSI i/o requests in mptsas_process_scsi_io_request(),
the Megaraid emulator appends new MPTSASRequest object 'req' to
the 's->pending' queue. In case of an error, this same object gets
dequeued in mptsas_free_request() only if SCSIRequest object
'req->sreq' is initialised. This may lead to a use-after-free issue.
Since MPTSASState.pending is actually not used, simply remove it.
"""
2/ Add:
BugLink: https://bugs.launchpad.net/qemu/+bug/1914236 (CVE-2021-3392)
Fixes: e351b826112 ("hw: Add support for LSI SAS1068 (mptsas) device")
With it:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
>>> Cc: Prasad J Pandit <pjp@fedoraproject.org>
>>> Cc: qemu-stable@nongnu.org
>>> ---
>>> hw/scsi/mptsas.c | 4 ----
>>> hw/scsi/mptsas.h | 1 -
>>> 2 files changed, 5 deletions(-)
>>>
>>> diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
>>> index 7416e78706..5abbc742aa 100644
>>> --- a/hw/scsi/mptsas.c
>>> +++ b/hw/scsi/mptsas.c
>>> @@ -257,7 +257,6 @@ static void mptsas_free_request(MPTSASRequest *req)
>>> req->sreq->hba_private = NULL;
>>> scsi_req_unref(req->sreq);
>>> req->sreq = NULL;
>>> - QTAILQ_REMOVE(&s->pending, req, next);
>>> }
>>> qemu_sglist_destroy(&req->qsg);
>>> g_free(req);
>>> @@ -303,7 +302,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
>>> }
>>>
>>> req = g_new0(MPTSASRequest, 1);
>>> - QTAILQ_INSERT_TAIL(&s->pending, req, next);
>>> req->scsi_io = *scsi_io;
>>> req->dev = s;
>>>
>>> @@ -1319,8 +1317,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
>>>
>>> s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
>>>
>>> - QTAILQ_INIT(&s->pending);
>>> -
>>> scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL);
>>> }
>>>
>>> diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
>>> index b85ac1a5fc..c046497db7 100644
>>> --- a/hw/scsi/mptsas.h
>>> +++ b/hw/scsi/mptsas.h
>>> @@ -79,7 +79,6 @@ struct MPTSASState {
>>> uint16_t reply_frame_size;
>>>
>>> SCSIBus bus;
>>> - QTAILQ_HEAD(, MPTSASRequest) pending;
>>> };
>>>
>>> void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);
>>>
>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH-for-6.0?] mptsas: remove unused MPTSASState.pending (CVE-2021-3392)
2021-04-18 5:14 ` Philippe Mathieu-Daudé
@ 2021-04-18 5:16 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-04-18 5:16 UTC (permalink / raw)
To: Michael Tokarev, qemu-devel, Fam Zheng, Paolo Bonzini
Cc: Peter Maydell, Prasad J Pandit, qemu-trivial, Don Slutz,
Li Qiang, qemu-stable, Cheolwoo Myung
On 4/18/21 7:14 AM, Philippe Mathieu-Daudé wrote:
> On 4/16/21 1:33 PM, Philippe Mathieu-Daudé wrote:
>> Cc'ing maintainers.
>>
>> On 4/16/21 1:27 PM, Philippe Mathieu-Daudé wrote:
>>> On 4/16/21 12:22 PM, Michael Tokarev wrote:
>>>> During previous attempt to fix CVE-2021-3392 it was discovered
>>>> that MPTSASState.pending is actually not used. So instead of
>>>> fixing the prob, just remove the offending code entirely
>>>
>>> What problem?
>
> Digging a bit I found:
> https://bugs.launchpad.net/qemu/+bug/1914236
> and Paolo's comment:
> https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg02660.html
>
> So your patch now makes sense, but please:
>
> 1/ Reword including Prasad description:
>
> """
> While processing SCSI i/o requests in mptsas_process_scsi_io_request(),
> the Megaraid emulator appends new MPTSASRequest object 'req' to
> the 's->pending' queue. In case of an error, this same object gets
> dequeued in mptsas_free_request() only if SCSIRequest object
> 'req->sreq' is initialised. This may lead to a use-after-free issue.
>
> Since MPTSASState.pending is actually not used, simply remove it.
> """
>
> 2/ Add:
>
> BugLink: https://bugs.launchpad.net/qemu/+bug/1914236 (CVE-2021-3392)
> Fixes: e351b826112 ("hw: Add support for LSI SAS1068 (mptsas) device")
And:
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
> With it:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>
>>>> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
>>>> Cc: Prasad J Pandit <pjp@fedoraproject.org>
>>>> Cc: qemu-stable@nongnu.org
>>>> ---
>>>> hw/scsi/mptsas.c | 4 ----
>>>> hw/scsi/mptsas.h | 1 -
>>>> 2 files changed, 5 deletions(-)
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-04-18 5:21 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-16 10:22 [PATCH] mptsas: remove unused MPTSASState.pending (CVE-2021-3392) Michael Tokarev
2021-04-16 11:27 ` [PATCH-for-6.0?] " Philippe Mathieu-Daudé
2021-04-16 11:33 ` Philippe Mathieu-Daudé
2021-04-18 5:14 ` Philippe Mathieu-Daudé
2021-04-18 5:16 ` Philippe Mathieu-Daudé
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