diff options
| -rw-r--r-- | security/selinux/hooks.c | 71 | ||||
| -rw-r--r-- | security/selinux/include/objsec.h | 1 |
2 files changed, 47 insertions, 25 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 973e31eb109..9d002f8484a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -161,7 +161,7 @@ static int task_alloc_security(struct task_struct *task) if (!tsec) return -ENOMEM; - tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED; + tsec->osid = tsec->sid = SECINITSID_UNLABELED; task->security = tsec; return 0; @@ -1671,19 +1671,13 @@ static inline u32 file_to_av(struct file *file) static int selinux_ptrace(struct task_struct *parent, struct task_struct *child) { - struct task_security_struct *psec = parent->security; - struct task_security_struct *csec = child->security; int rc; rc = secondary_ops->ptrace(parent,child); if (rc) return rc; - rc = task_has_perm(parent, child, PROCESS__PTRACE); - /* Save the SID of the tracing process for later use in apply_creds. */ - if (!(child->ptrace & PT_PTRACED) && !rc) - csec->ptrace_sid = psec->sid; - return rc; + return task_has_perm(parent, child, PROCESS__PTRACE); } static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, @@ -1905,6 +1899,22 @@ 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) @@ -2151,12 +2161,25 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and kill. */ if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { - rc = avc_has_perm(tsec->ptrace_sid, sid, - SECCLASS_PROCESS, PROCESS__PTRACE, - NULL); - if (rc) { - bsec->unsafe = 1; - return; + struct task_struct *tracer; + struct task_security_struct *sec; + u32 ptsid = 0; + + rcu_read_lock(); + tracer = task_tracer_task(current); + if (likely(tracer != NULL)) { + sec = tracer->security; + ptsid = sec->sid; + } + rcu_read_unlock(); + + if (ptsid != 0) { + rc = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, + PROCESS__PTRACE, NULL); + if (rc) { + bsec->unsafe = 1; + return; + } } } tsec->sid = sid; @@ -3112,11 +3135,6 @@ static int selinux_task_alloc_security(struct task_struct *tsk) tsec2->keycreate_sid = tsec1->keycreate_sid; tsec2->sockcreate_sid = tsec1->sockcreate_sid; - /* Retain ptracer SID across fork, if any. - This will be reset by the ptrace hook upon any - subsequent ptrace_attach operations. */ - tsec2->ptrace_sid = tsec1->ptrace_sid; - return 0; } @@ -5080,6 +5098,7 @@ static int selinux_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { struct task_security_struct *tsec; + struct task_struct *tracer; u32 sid = 0; int error; char *str = value; @@ -5168,18 +5187,24 @@ static int selinux_setprocattr(struct task_struct *p, /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ task_lock(p); - if (p->ptrace & PT_PTRACED) { - error = avc_has_perm_noaudit(tsec->ptrace_sid, sid, + rcu_read_lock(); + tracer = task_tracer_task(p); + if (tracer != NULL) { + struct task_security_struct *ptsec = tracer->security; + u32 ptsid = ptsec->sid; + rcu_read_unlock(); + error = avc_has_perm_noaudit(ptsid, sid, SECCLASS_PROCESS, PROCESS__PTRACE, 0, &avd); if (!error) tsec->sid = sid; task_unlock(p); - avc_audit(tsec->ptrace_sid, sid, SECCLASS_PROCESS, + avc_audit(ptsid, sid, SECCLASS_PROCESS, PROCESS__PTRACE, &avd, error, NULL); if (error) return error; } else { + rcu_read_unlock(); tsec->sid = sid; task_unlock(p); } @@ -5653,5 +5678,3 @@ int selinux_disable(void) return 0; } #endif - - diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 020a8754b80..957b10d0f76 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -34,7 +34,6 @@ struct task_security_struct { u32 create_sid; /* fscreate SID */ u32 keycreate_sid; /* keycreate SID */ u32 sockcreate_sid; /* fscreate SID */ - u32 ptrace_sid; /* SID of ptrace parent */ }; struct inode_security_struct { |