From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: linux-kernel@vger.kernel.org,
George Zhang <georgezhang@vmware.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
kernel-janitors@vger.kernel.org
Subject: Re: [patch] VMCI: integer overflow in vmci_datagram_dispatch()
Date: Fri, 29 Aug 2014 11:21:04 +0000 [thread overview]
Message-ID: <20140829112104.GF5071@mwanda> (raw)
In-Reply-To: <5400606B.8010905@bfs.de>
On Fri, Aug 29, 2014 at 01:13:47PM +0200, walter harms wrote:
>
>
> Am 29.08.2014 10:42, schrieb Dan Carpenter:
> > This is untrusted user data from vmci_host_do_send_datagram() so the
> > VMCI_DG_SIZE() macro can have an integer overflow.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >
> > diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c
> > index f3cdd90..8226652 100644
> > --- a/drivers/misc/vmw_vmci/vmci_datagram.c
> > +++ b/drivers/misc/vmw_vmci/vmci_datagram.c
> > @@ -328,7 +328,8 @@ int vmci_datagram_dispatch(u32 context_id,
> >
> > BUILD_BUG_ON(sizeof(struct vmci_datagram) != 24);
> >
> > - if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
> > + if (dg->payload_size > VMCI_MAX_DG_SIZE ||
> > + VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
> > pr_devel("Payload (size=%llu bytes) too big to send\n",
> > (unsigned long long)dg->payload_size);
> > return VMCI_ERROR_INVALID_ARGS;
>
> Are your sure about that ">" ? maybe ">=" was intended ?
Yes, I'm sure. As a rule of thumb, > is used for size comparisons and
>= is used for index comparisons.
regards,
dan carpenter
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: linux-kernel@vger.kernel.org,
George Zhang <georgezhang@vmware.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
kernel-janitors@vger.kernel.org
Subject: Re: [patch] VMCI: integer overflow in vmci_datagram_dispatch()
Date: Fri, 29 Aug 2014 14:21:04 +0300 [thread overview]
Message-ID: <20140829112104.GF5071@mwanda> (raw)
In-Reply-To: <5400606B.8010905@bfs.de>
On Fri, Aug 29, 2014 at 01:13:47PM +0200, walter harms wrote:
>
>
> Am 29.08.2014 10:42, schrieb Dan Carpenter:
> > This is untrusted user data from vmci_host_do_send_datagram() so the
> > VMCI_DG_SIZE() macro can have an integer overflow.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >
> > diff --git a/drivers/misc/vmw_vmci/vmci_datagram.c b/drivers/misc/vmw_vmci/vmci_datagram.c
> > index f3cdd90..8226652 100644
> > --- a/drivers/misc/vmw_vmci/vmci_datagram.c
> > +++ b/drivers/misc/vmw_vmci/vmci_datagram.c
> > @@ -328,7 +328,8 @@ int vmci_datagram_dispatch(u32 context_id,
> >
> > BUILD_BUG_ON(sizeof(struct vmci_datagram) != 24);
> >
> > - if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
> > + if (dg->payload_size > VMCI_MAX_DG_SIZE ||
> > + VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE) {
> > pr_devel("Payload (size=%llu bytes) too big to send\n",
> > (unsigned long long)dg->payload_size);
> > return VMCI_ERROR_INVALID_ARGS;
>
> Are your sure about that ">" ? maybe ">=" was intended ?
Yes, I'm sure. As a rule of thumb, > is used for size comparisons and
>= is used for index comparisons.
regards,
dan carpenter
next prev parent reply other threads:[~2014-08-29 11:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-29 8:42 [patch] VMCI: integer overflow in vmci_datagram_dispatch() Dan Carpenter
2014-08-29 8:42 ` Dan Carpenter
2014-08-29 11:13 ` walter harms
2014-08-29 11:13 ` walter harms
2014-08-29 11:21 ` Dan Carpenter [this message]
2014-08-29 11:21 ` Dan Carpenter
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