From: Sascha Wildner <saw@online.de>
Date: Tue, 21 Aug 2012 20:44:09 +0000 (+0200)
Subject: kernel/linprocfs: Fix a panic when accessing /proc/<pid>/maps.
X-Git-Tag: v3.0.3^2~1
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/f8183e2028afe1d0464a79b17e0ae303e0fb7d71

kernel/linprocfs: Fix a panic when accessing /proc/<pid>/maps.

Analogous to procfs.
---

diff --git a/sys/emulation/linux/i386/linprocfs/linprocfs_misc.c b/sys/emulation/linux/i386/linprocfs/linprocfs_misc.c
index 0fb4e4f..e592668 100644
--- a/sys/emulation/linux/i386/linprocfs/linprocfs_misc.c
+++ b/sys/emulation/linux/i386/linprocfs/linprocfs_misc.c
@@ -754,7 +754,8 @@ linprocfs_domaps(struct proc *curp, struct proc *p, struct pfsnode *pfs,
 		 * if they happen to be the same).
 		 */
 		obj = entry->object.vm_object;
-                vm_object_hold(obj);
+		if (obj)
+			vm_object_hold(obj);
 
                 lobj = obj;
                 while (lobj && (tobj = lobj->backing_object) != NULL) {
@@ -798,7 +799,8 @@ linprocfs_domaps(struct proc *curp, struct proc *p, struct pfsnode *pfs,
 
 		if (lobj != obj)
 			vm_object_drop(lobj);
-		vm_object_drop(obj);
+		if (obj)
+			vm_object_drop(obj);
 
 		/*
 		 * We cannot safely hold the map locked while accessing