From 1dbf9dcc20ca9dcb5fde8e70f32760c3f165f3d0 Mon Sep 17 00:00:00 2001
From: Edward Tomasz Napierala <trasz@FreeBSD.org>
Date: Sat, 17 Sep 2011 20:48:49 +0000
Subject: [PATCH] Fix error handling bug that would prevent MAC structures from
 getting freed properly if resource limit got exceeded.

Approved by:	re (kib)
---
 sys/kern/kern_fork.c | 38 ++++++++++++++++++--------------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 0a27cc02040..a3634b7aa1c 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -863,11 +863,6 @@ fork1(struct thread *td, int flags, int pages, struct proc **procp,
 		}
 	} else
 		vm2 = NULL;
-#ifdef MAC
-	mac_proc_init(newproc);
-#endif
-	knlist_init_mtx(&newproc->p_klist, &newproc->p_mtx);
-	STAILQ_INIT(&newproc->p_ktr);
 
 	/*
 	 * XXX: This is ugly; when we copy resource usage, we need to bump
@@ -884,6 +879,23 @@ fork1(struct thread *td, int flags, int pages, struct proc **procp,
 		goto fail1;
 	}
 
+#ifdef RACCT
+	PROC_LOCK(newproc);
+	error = racct_add(newproc, RACCT_NPROC, 1);
+	error += racct_add(newproc, RACCT_NTHR, 1);
+	PROC_UNLOCK(newproc);
+	if (error != 0) {
+		error = EAGAIN;
+		goto fail1;
+	}
+#endif
+
+#ifdef MAC
+	mac_proc_init(newproc);
+#endif
+	knlist_init_mtx(&newproc->p_klist, &newproc->p_mtx);
+	STAILQ_INIT(&newproc->p_ktr);
+
 	/* We have to lock the process tree while we look for a pid. */
 	sx_slock(&proctree_lock);
 
@@ -901,20 +913,6 @@ fork1(struct thread *td, int flags, int pages, struct proc **procp,
 		goto fail;
 	}
 
-#ifdef RACCT
-	/*
-	 * After fork, there is exactly one thread running.
-	 */
-	PROC_LOCK(newproc);
-	error = racct_add(newproc, RACCT_NPROC, 1);
-	error += racct_add(newproc, RACCT_NTHR, 1);
-	PROC_UNLOCK(newproc);
-	if (error != 0) {
-		error = EAGAIN;
-		goto fail;
-	}
-#endif
-
 	/*
 	 * Increment the count of procs running with this uid. Don't allow
 	 * a nonprivileged user to exceed their current limit.
@@ -946,7 +944,6 @@ fork1(struct thread *td, int flags, int pages, struct proc **procp,
 
 	error = EAGAIN;
 fail:
-	racct_proc_exit(newproc);
 	sx_sunlock(&proctree_lock);
 	if (ppsratecheck(&lastfail, &curfail, 1))
 		printf("maxproc limit exceeded by uid %i, please see tuning(7) and login.conf(5).\n",
@@ -956,6 +953,7 @@ fail:
 	mac_proc_destroy(newproc);
 #endif
 fail1:
+	racct_proc_exit(newproc);
 	if (vm2 != NULL)
 		vmspace_free(vm2);
 	uma_zfree(proc_zone, newproc);