CVE-2017-5753 (Spectre v1 Intel)
Since the fd value in function __fcheck_files()
seems to be controllable by userspace and later on
conditionally (upon bound check) used to resolve
fdt->fd, insert an observable speculation
barrier before its usage. This should prevent
observable speculation on that branch and avoid
kernel memory leak.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
{
struct fdtable *fdt = rcu_dereference_raw(files->fdt);
- if (fd < fdt->max_fds)
+ if (fd < fdt->max_fds) {
+ osb();
return rcu_dereference_raw(fdt->fd[fd]);
+ }
return NULL;
}