diff options
| -rw-r--r-- | security/yama/yama_lsm.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 0309f2111c70..968e5e0a3f81 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -309,7 +309,7 @@ static int task_is_descendant(struct task_struct *parent, * @tracer: the task_struct of the process attempting ptrace * @tracee: the task_struct of the process to be ptraced * - * Returns 1 if tracer has is ptracer exception ancestor for tracee. + * Returns 1 if tracer has a ptracer exception ancestor for tracee. */ static int ptracer_exception_found(struct task_struct *tracer, struct task_struct *tracee) @@ -320,6 +320,18 @@ static int ptracer_exception_found(struct task_struct *tracer, bool found = false; rcu_read_lock(); + + /* + * If there's already an active tracing relationship, then make an + * exception for the sake of other accesses, like process_vm_rw(). + */ + parent = ptrace_parent(tracee); + if (parent != NULL && same_thread_group(parent, tracer)) { + rc = 1; + goto unlock; + } + + /* Look for a PR_SET_PTRACER relationship. */ if (!thread_group_leader(tracee)) tracee = rcu_dereference(tracee->group_leader); list_for_each_entry_rcu(relation, &ptracer_relations, node) { @@ -334,6 +346,8 @@ static int ptracer_exception_found(struct task_struct *tracer, if (found && (parent == NULL || task_is_descendant(parent, tracer))) rc = 1; + +unlock: rcu_read_unlock(); return rc; |