5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hagar Gamal Halim Hemdan hagarhem@amazon.com
commit 8003f00d895310d409b2bf9ef907c56b42a4e0f4 upstream.
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.
This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc.
Only compile tested, no access to HW.
Fixes: 1d990201f9bb ("VMCI: event handling implementation.") Cc: stable stable@kernel.org Signed-off-by: Hagar Gamal Halim Hemdan hagarhem@amazon.com Link: https://lore.kernel.org/stable/20231127193533.46174-1-hagarhem%40amazon.com Link: https://lore.kernel.org/r/20240430085916.4753-1-hagarhem@amazon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/vmw_vmci/vmci_event.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- 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_ev { 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);