selinux: check sidtab limit before adding a new entry
We need to error out when trying to add an entry above SIDTAB_MAX in
sidtab_reverse_lookup() to avoid overflow on the odd chance that this
happens.
Cc: stable@vger.kernel.org
Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index e63a90f..1f0a6ea 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -286,6 +286,11 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
++count;
}
+ /* bail out if we already reached max entries */
+ rc = -EOVERFLOW;
+ if (count >= SIDTAB_MAX)
+ goto out_unlock;
+
/* insert context into new entry */
rc = -ENOMEM;
dst = sidtab_do_lookup(s, count, 1);