From: Dmitry Fleytman <dmitry@daynix.com>
To: P J P <ppandit@redhat.com>
Cc: Qinghao Tang <luodalongde@gmail.com>,
Jason Wang <jasowang@redhat.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] net: vmxnet3: memory leakage issue
Date: Sun, 13 Dec 2015 10:27:20 +0200 [thread overview]
Message-ID: <B70517D2-5032-4E08-AC11-7E0E63C165E8@daynix.com> (raw)
In-Reply-To: <alpine.LFD.2.20.1512111512110.13222@wniryva>
> On 11 Dec 2015, at 12:04 PM, P J P <ppandit@redhat.com> wrote:
>
> Hello Jason,
>
> +-- On Fri, 11 Dec 2015, Jason Wang wrote --+
> | I think it's possible for attacker. Better wait for Dmitry's answer for
> | this.
>
> Okay.
>
> | > + /* Verify if device is active */
> | > + if (s->device_active) {
> | > + VMW_CFPRN("Vmxnet3 device is active");
> | > + return;
> | > + }
> |
> | What if guest want to activate a paused device?
>
> There is a 'resume' operation defined below.
>
> | > case VMXNET3_CMD_QUIESCE_DEV:
> | > - VMW_CBPRN("Set: VMXNET3_CMD_QUIESCE_DEV - pause the device");
> | > - vmxnet3_deactivate_device(s);
> | > + if (s->device_active & VMXNET3_DEV_ACTIVE) {
> | > + VMW_CBPRN("Set: VMXNET3_CMD_QUIESCE_DEV - pause the device");
> | > + vmxnet3_pause_device(s);
> | > + } else if (s->device_active & VMXNET3_DEV_PAUSE) {
> | > + VMW_CBPRN("Set: VMXNET3_CMD_QUIESCE_DEV - resume the device");
> | > + vmxnet3_resume_device(s);
> | > + }
> |
> | Not sure this is the correct behavior. Is there a link to the spec?
>
> I couldn't find a spec for vmxnet3; I referred the vmxnet3 kernel driver,
> which seems to implement suspend & resume functions.
Unfortunately the spec is not available.
The device was implemented using Linux/Windows drivers as references.
>
> -> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/net/vmxnet3/vmxnet3_drv.c
>
> In general, Ethernet documents talk about 'pause' frame mechanism to stop NIC
> from buffering more data, till it has space available to process more, when it
> resumes its operation.
>
> Thank you.
> --
> Prasad J Pandit / Red Hat Product Security Team
> 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
next prev parent reply other threads:[~2015-12-13 8:27 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-02 12:17 [Qemu-devel] net: vmxnet3: memory leakage issue P J P
2015-12-03 7:17 ` Dmitry Fleytman
2015-12-03 11:20 ` P J P
2015-12-04 3:16 ` Jason Wang
2015-12-08 10:17 ` P J P
2015-12-09 15:28 ` P J P
2015-12-11 9:10 ` Jason Wang
2015-12-11 9:34 ` Dmitry Fleytman
2015-12-11 10:04 ` P J P
2015-12-13 8:27 ` Dmitry Fleytman [this message]
2015-12-13 9:45 ` Dmitry Fleytman
2015-12-14 11:58 ` P J P
2015-12-14 17:27 ` Dmitry Fleytman
2015-12-15 6:57 ` P J P
2015-12-15 7:01 ` Dmitry Fleytman
2015-12-15 8:00 ` P J P
2015-12-15 8:24 ` Jason Wang
2015-12-15 8:50 ` P J P
2015-12-15 8:43 ` Miao Yan
2015-12-15 10:08 ` P J P
2015-12-04 2:22 ` Jason Wang
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