diff options
| -rw-r--r-- | fs/proc/array.c | 9 | ||||
| -rw-r--r-- | fs/proc/base.c | 13 | ||||
| -rw-r--r-- | include/linux/tracehook.h | 18 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 22 |
4 files changed, 37 insertions, 25 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 797d775e0354..0d6eb33597c6 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -80,6 +80,7 @@ #include <linux/delayacct.h> #include <linux/seq_file.h> #include <linux/pid_namespace.h> +#include <linux/tracehook.h> #include <asm/pgtable.h> #include <asm/processor.h> @@ -168,8 +169,12 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, rcu_read_lock(); ppid = pid_alive(p) ? task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0; - tpid = pid_alive(p) && p->ptrace ? - task_pid_nr_ns(rcu_dereference(p->parent), ns) : 0; + tpid = 0; + if (pid_alive(p)) { + struct task_struct *tracer = tracehook_tracer_task(p); + if (tracer) + tpid = task_pid_nr_ns(tracer, ns); + } seq_printf(m, "State:\t%s\n" "Tgid:\t%d\n" diff --git a/fs/proc/base.c b/fs/proc/base.c index a891fe4cb43b..4b74dba69a6d 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -69,6 +69,7 @@ #include <linux/mount.h> #include <linux/security.h> #include <linux/ptrace.h> +#include <linux/tracehook.h> #include <linux/cgroup.h> #include <linux/cpuset.h> #include <linux/audit.h> @@ -231,10 +232,14 @@ static int check_mem_permission(struct task_struct *task) * If current is actively ptrace'ing, and would also be * permitted to freshly attach with ptrace now, permit it. */ - if (task->parent == current && (task->ptrace & PT_PTRACED) && - task_is_stopped_or_traced(task) && - ptrace_may_access(task, PTRACE_MODE_ATTACH)) - return 0; + if (task_is_stopped_or_traced(task)) { + int match; + rcu_read_lock(); + match = (tracehook_tracer_task(task) == current); + rcu_read_unlock(); + if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH)) + return 0; + } /* * Noone else is allowed. diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 9a5b3be2503a..6468ca0fe69b 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -73,6 +73,24 @@ static inline int tracehook_unsafe_exec(struct task_struct *task) } /** + * tracehook_tracer_task - return the task that is tracing the given task + * @tsk: task to consider + * + * Returns NULL if noone is tracing @task, or the &struct task_struct + * pointer to its tracer. + * + * Must called under rcu_read_lock(). The pointer returned might be kept + * live only by RCU. During exec, this may be called with task_lock() + * held on @task, still held from when tracehook_unsafe_exec() was called. + */ +static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk) +{ + if (task_ptrace(tsk) & PT_PTRACED) + return rcu_dereference(tsk->parent); + return NULL; +} + +/** * tracehook_report_exec - a successful exec was completed * @fmt: &struct linux_binfmt that performed the exec * @bprm: &struct linux_binprm containing exec details diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 63f131fc42e4..3481cde5bf15 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -25,7 +25,7 @@ #include <linux/init.h> #include <linux/kernel.h> -#include <linux/ptrace.h> +#include <linux/tracehook.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/security.h> @@ -1971,22 +1971,6 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) return __vm_enough_memory(mm, pages, cap_sys_admin); } -/** - * task_tracer_task - return the task that is tracing the given task - * @task: task to consider - * - * Returns NULL if noone is tracing @task, or the &struct task_struct - * pointer to its tracer. - * - * Must be called under rcu_read_lock(). - */ -static struct task_struct *task_tracer_task(struct task_struct *task) -{ - if (task->ptrace & PT_PTRACED) - return rcu_dereference(task->parent); - return NULL; -} - /* binprm security operations */ static int selinux_bprm_alloc_security(struct linux_binprm *bprm) @@ -2238,7 +2222,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) u32 ptsid = 0; rcu_read_lock(); - tracer = task_tracer_task(current); + tracer = tracehook_tracer_task(current); if (likely(tracer != NULL)) { sec = tracer->security; ptsid = sec->sid; @@ -5247,7 +5231,7 @@ static int selinux_setprocattr(struct task_struct *p, Otherwise, leave SID unchanged and fail. */ task_lock(p); rcu_read_lock(); - tracer = task_tracer_task(p); + tracer = tracehook_tracer_task(p); if (tracer != NULL) { struct task_security_struct *ptsec = tracer->security; u32 ptsid = ptsec->sid; |