[v3] virtio,pci,pc: features,fixes,cleanups

[PULL v3 17/55] vhost-backend: avoid overflow on memslots_limit

Michael S. Tsirkin posted 55 patches 4 years, 1 month ago

Diff against v1 v2
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Maintainers: Richard Henderson <richard.henderson@linaro.org>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Jason Wang <jasowang@redhat.com>, Shannon Zhao <shannon.zhaosl@gmail.com>, Peter Maydell <peter.maydell@linaro.org>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Ani Sinha <ani@anisinha.ca>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Michael S. Tsirkin" <mst@redhat.com>, Raphael Norwitz <raphael.norwitz@nutanix.com>, Igor Mammedov <imammedo@redhat.com>, Peter Xu <peterx@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Kevin Wolf <kwolf@redhat.com>, David Hildenbrand <david@redhat.com>, "Gonglei (Arei)" <arei.gonglei@huawei.com>, Hanna Reitz <hreitz@redhat.com>, Fam Zheng <fam@euphon.net>

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[PULL v3 17/55] vhost-backend: avoid overflow on memslots_limit

Posted by Michael S. Tsirkin 4 years, 1 month ago

From: Roman Kagan <rvkagan@yandex-team.ru>

Fix the (hypothetical) potential problem when the value parsed out of
the vhost module parameter in sysfs overflows the return value from
vhost_kernel_memslots_limit.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Message-Id: <20211111153354.18807-6-rvkagan@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-backend.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index b65f8f7e97..44f7dbb243 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -58,7 +58,7 @@ static int vhost_kernel_memslots_limit(struct vhost_dev *dev)
     if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions",
                             &s, NULL, NULL)) {
         uint64_t val = g_ascii_strtoull(s, NULL, 10);
-        if (!((val == G_MAXUINT64 || !val) && errno)) {
+        if (val < INT_MAX && val > 0) {
             g_free(s);
             return val;
         }
-- 
MST