doc/share/security/patches/EN-09:05/null.patch
Bjoern A. Zeeb 3571e53040 Import FreeBSD Security Advisories and Errata Notices, as well as their
patches for easier mirroring, to eliminate a special copy, to make
www.freebsd.org/security a full copy of security.freebsd.org and be
eventually be the same.

For now files are just sitting there.   The symlinks are missing.

Discussed on:	www (repository location)
Discussed with:	simon (so)
2012-08-15 06:19:40 +00:00

45 lines
1.4 KiB
Diff

Index: sys/kern/kern_exec.c
===================================================================
--- sys/kern/kern_exec.c (revision 197682)
+++ sys/kern/kern_exec.c (working copy)
@@ -122,6 +122,11 @@
SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
&ps_arg_cache_limit, 0, "");
+static int map_at_zero = 1;
+TUNABLE_INT("security.bsd.map_at_zero", &map_at_zero);
+SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RW, &map_at_zero, 0,
+ "Permit processes to map an object at virtual address 0.");
+
static int
sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
{
@@ -939,7 +944,7 @@
int error;
struct proc *p = imgp->proc;
struct vmspace *vmspace = p->p_vmspace;
- vm_offset_t stack_addr;
+ vm_offset_t sv_minuser, stack_addr;
vm_map_t map;
u_long ssiz;
@@ -955,13 +960,17 @@
* not disrupted
*/
map = &vmspace->vm_map;
- if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv->sv_minuser &&
+ if (map_at_zero)
+ sv_minuser = sv->sv_minuser;
+ else
+ sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
+ if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
vm_map_max(map) == sv->sv_maxuser) {
shmexit(vmspace);
pmap_remove_pages(vmspace_pmap(vmspace));
vm_map_remove(map, vm_map_min(map), vm_map_max(map));
} else {
- error = vmspace_exec(p, sv->sv_minuser, sv->sv_maxuser);
+ error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
if (error)
return (error);
vmspace = p->p_vmspace;