From: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
To: sgarzare@redhat.com
Cc: harshit.m.mogalapalli@oracle.com, error27@gmail.com,
harshit.m.mogalapalli@gmail.com,
"Michael S . Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Xie Yongji <xieyongji@bytedance.com>,
Gautam Dawar <gautam.dawar@xilinx.com>,
Maxime Coquelin <maxime.coquelin@redhat.com>,
Parav Pandit <parav@nvidia.com>, Eli Cohen <elic@nvidia.com>,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v3] vduse: Validate vq_num in vduse_validate_config()
Date: Mon, 28 Nov 2022 07:57:15 -0800 [thread overview]
Message-ID: <20221128155717.2579992-1-harshit.m.mogalapalli@oracle.com> (raw)
Add a limit to 'config->vq_num' which is user controlled data which
comes from an vduse_ioctl to prevent large memory allocations.
Micheal says - This limit is somewhat arbitrary.
However, currently virtio pci and ccw are limited to a 16 bit vq number.
While MMIO isn't it is also isn't used with lots of VQs due to
current lack of support for per-vq interrupts.
Thus, the 0xffff limit on number of VQs corresponding
to a 16-bit VQ number seems sufficient for now.
This is found using static analysis with smatch.
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
---
v1->v2: Change title of the commit and description, add a limit to
vq_num.
v2->v3: Improve commit message to include reason for setting limit to
0xffff
Only compile and boot tested.
---
drivers/vdpa/vdpa_user/vduse_dev.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 35dceee3ed56..31017ebc4d7c 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1440,6 +1440,9 @@ static bool vduse_validate_config(struct vduse_dev_config *config)
if (config->config_size > PAGE_SIZE)
return false;
+ if (config->vq_num > 0xffff)
+ return false;
+
if (!device_is_allowed(config->device_id))
return false;
--
2.38.1
next reply other threads:[~2022-11-28 15:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-28 15:57 Harshit Mogalapalli [this message]
2022-11-29 2:59 ` [PATCH v3] vduse: Validate vq_num in vduse_validate_config() Jason Wang
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