From a5b7fde7222ddaf6a84d43615f1640eaf1da1db5 Mon Sep 17 00:00:00 2001 From: "Christian S.J. Peron" Date: Sun, 9 Oct 2005 02:37:27 +0000 Subject: [PATCH] Lock object while we iterate through it's backing objects. Discussed with: alc --- sys/security/mac/mac_process.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/sys/security/mac/mac_process.c b/sys/security/mac/mac_process.c index 67bda6fa7742..9b72cbd5cc04 100644 --- a/sys/security/mac/mac_process.c +++ b/sys/security/mac/mac_process.c @@ -327,7 +327,7 @@ mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred, struct vm_map_entry *vme; int vfslocked, result; vm_prot_t revokeperms; - vm_object_t object; + vm_object_t backing_object, object; vm_ooffset_t offset; struct vnode *vp; @@ -354,13 +354,14 @@ mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred, object = vme->object.vm_object; if (object == NULL) continue; - /* XXXCSJP We need to lock the object before walking - * the backing object list. - */ - while (object->backing_object != NULL) { + VM_OBJECT_LOCK(object); + while ((backing_object = object->backing_object) != NULL) { + VM_OBJECT_LOCK(backing_object); offset += object->backing_object_offset; - object = object->backing_object; + VM_OBJECT_UNLOCK(object); + object = backing_object; } + VM_OBJECT_UNLOCK(object); /* * At the moment, vm_maps and objects aren't considered * by the MAC system, so only things with backing by a