xnu-7195.60.75.tar.gz

[apple/xnu.git] / bsd / dev / dtrace / fasttrap.c

diff --git a/bsd/dev/dtrace/fasttrap.c b/bsd/dev/dtrace/fasttrap.c
index b519a7a3b961a13794e6e39cfb53782671f753b6..e95eb2e1fe259150f33bf06544937f9ff5f7b2e6 100644 (file)
--- a/bsd/dev/dtrace/fasttrap.c
+++ b/bsd/dev/dtrace/fasttrap.c
@@ -2415,6 +2415,48 @@ fasttrap_validatestr(char const* str, size_t maxlen) {
        return utf8_validatestr((unsigned const char*) str, len);
 }
 
+/*
+ * Checks that provided credentials are allowed to debug target process.
+ */
+static int
+fasttrap_check_cred_priv(cred_t *cr, proc_t *p)
+{
+       int err = 0;
+
+       /* Only root can use DTrace. */
+       if (!kauth_cred_issuser(cr)) {
+               err = EPERM;
+               goto out;
+       }
+
+       /* Process is marked as no attach. */
+       if (ISSET(p->p_lflag, P_LNOATTACH)) {
+               err = EBUSY;
+               goto out;
+       }
+
+#if CONFIG_MACF
+       /* Check with MAC framework when enabled. */
+       struct proc_ident cur_ident = proc_ident(current_proc());
+       struct proc_ident p_ident = proc_ident(p);
+
+       /* Do not hold ref to proc here to avoid deadlock. */
+       proc_rele(p);
+       err = mac_proc_check_debug(&cur_ident, cr, &p_ident);
+
+       if (proc_find_ident(&p_ident) == PROC_NULL) {
+               err = ESRCH;
+               goto out_no_proc;
+       }
+#endif /* CONFIG_MACF */
+
+out:
+       proc_rele(p);
+
+out_no_proc:
+       return err;
+}
+
 /*ARGSUSED*/
 static int
 fasttrap_ioctl(dev_t dev, u_long cmd, user_addr_t arg, int md, cred_t *cr, int *rv)
@@ -2486,15 +2528,11 @@ fasttrap_ioctl(dev_t dev, u_long cmd, user_addr_t arg, int md, cred_t *cr, int *
                                ret = ESRCH;
                                goto err;
                        }
-                       // proc_lock(p);
-                       // FIXME! How is this done on OS X?
-                       // if ((ret = priv_proc_cred_perm(cr, p, NULL,
-                       //     VREAD | VWRITE)) != 0) {
-                       //      mutex_exit(&p->p_lock);
-                       //      return (ret);
-                       // }
-                       // proc_unlock(p);
-                       proc_rele(p);
+
+                       ret = fasttrap_check_cred_priv(cr, p);
+                       if (ret != 0) {
+                               goto err;
+                       }
                }
 
                ret = fasttrap_add_probe(probe);
@@ -2508,7 +2546,7 @@ err:
                fasttrap_instr_query_t instr;
                fasttrap_tracepoint_t *tp;
                uint_t index;
-               // int ret;
+               int ret;
 
                if (copyin(arg, &instr, sizeof (instr)) != 0)
                        return (EFAULT);
@@ -2526,15 +2564,11 @@ err:
                                        proc_rele(p);
                                return (ESRCH);
                        }
-                       //proc_lock(p);
-                       // FIXME! How is this done on OS X?
-                       // if ((ret = priv_proc_cred_perm(cr, p, NULL,
-                       //     VREAD)) != 0) {
-                       //      mutex_exit(&p->p_lock);
-                       //      return (ret);
-                       // }
-                       // proc_unlock(p);
-                       proc_rele(p);
+
+                       ret = fasttrap_check_cred_priv(cr, p);
+                       if (ret != 0) {
+                               return (ret);
+                       }
                }
 
                index = FASTTRAP_TPOINTS_INDEX(instr.ftiq_pid, instr.ftiq_pc);