From 51775fe736f053329faf0f5de7c679ee4cb0023d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 8 Oct 2013 05:46:03 -0700 Subject: [PATCH] apparmor: remove the "task" arg from may_change_ptraced_domain() Unless task == current ptrace_parent(task) is not safe even under rcu_read_lock() and most of the current users are not right. So may_change_ptraced_domain(task) looks wrong as well. However it is always called with task == current so the code is actually fine. Remove this argument to make this fact clear. Note: perhaps we should simply kill ptrace_parent(), it buys almost nothing. And it is obviously racy, perhaps this should be fixed. Signed-off-by: Oleg Nesterov Signed-off-by: John Johansen --- security/apparmor/domain.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index e5538a12d162..452567d3a08e 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -50,23 +50,21 @@ void aa_free_domain_entries(struct aa_domain *domain) /** * may_change_ptraced_domain - check if can change profile on ptraced task - * @task: task we want to change profile of (NOT NULL) * @to_profile: profile to change to (NOT NULL) * - * Check if the task is ptraced and if so if the tracing task is allowed + * Check if current is ptraced and if so if the tracing task is allowed * to trace the new domain * * Returns: %0 or error if change not allowed */ -static int may_change_ptraced_domain(struct task_struct *task, - struct aa_profile *to_profile) +static int may_change_ptraced_domain(struct aa_profile *to_profile) { struct task_struct *tracer; struct aa_profile *tracerp = NULL; int error = 0; rcu_read_lock(); - tracer = ptrace_parent(task); + tracer = ptrace_parent(current); if (tracer) /* released below */ tracerp = aa_get_task_profile(tracer); @@ -477,7 +475,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) } if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { - error = may_change_ptraced_domain(current, new_profile); + error = may_change_ptraced_domain(new_profile); if (error) { aa_put_profile(new_profile); goto audit; @@ -690,7 +688,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest) } } - error = may_change_ptraced_domain(current, hat); + error = may_change_ptraced_domain(hat); if (error) { info = "ptraced"; error = -EPERM; @@ -829,7 +827,7 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec, } /* check if tracing task is allowed to trace target domain */ - error = may_change_ptraced_domain(current, target); + error = may_change_ptraced_domain(target); if (error) { info = "ptrace prevents transition"; goto audit; -- 2.20.1