On Tue, Nov 28, 2023 at 08:36:58AM +0000, Hagar Gamal Halim Hemdan wrote:

Coverity spotted that event_msg is controlled by user-space, event_msg->event_data.event is passed to event_deliver() and used as an index without sanitization.

This change ensures that the event index is sanitized to mitigate any possibility of speculative information leaks.

Fixes: 1d990201f9bb ("VMCI: event handling implementation.")

Signed-off-by: Hagar Gamal Halim Hemdan hagarhem@amazon.com Cc: stable@vger.kernel.org

---

drivers/misc/vmw_vmci/vmci_event.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/vmw_vmci/vmci_event.c b/drivers/misc/vmw_vmci/vmci_event.c index 5d7ac07623c2..9a41ab65378d 100644 --- a/drivers/misc/vmw_vmci/vmci_event.c +++ b/drivers/misc/vmw_vmci/vmci_event.c @@ -9,6 +9,7 @@ #include <linux/vmw_vmci_api.h> #include <linux/list.h> #include <linux/module.h> +#include <linux/nospec.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/rculist.h> @@ -86,9 +87,12 @@ static void event_deliver(struct vmci_event_msg *event_msg) { struct vmci_subscription *cur; struct list_head *subscriber_list;

• u32 sanitized_event, max_vmci_event;

rcu_read_lock();

• subscriber_list = &subscriber_array[event_msg->event_data.event];

• max_vmci_event = ARRAY_SIZE(subscriber_array);
• sanitized_event = array_index_nospec(event_msg->event_data.event, max_vmci_event);
• subscriber_list = &subscriber_array[sanitized_event]; list_for_each_entry_rcu(cur, subscriber_list, node) { cur->callback(cur->id, &event_msg->event_data, cur->callback_data);

-- 2.40.1

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