MFC r321173:

Convert assertion that only vmspace owner grows the stack, into a
check blocking grow from other processes accesses.

MFC r321230:
Disable stack growth when accessed by AIO daemons.

1 files changed, 9 insertions, 1 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index c9815c0..3a83252 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -3700,7 +3700,15 @@ vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
 
 	p = curproc;
 	vm = p->p_vmspace;
-	MPASS(map == &p->p_vmspace->vm_map);
+
+	/*
+	 * Disallow stack growth when the access is performed by a
+	 * debugger or AIO daemon.  The reason is that the wrong
+	 * resource limits are applied.
+	 */
+	if (map != &p->p_vmspace->vm_map || p->p_textvp == NULL)
+		return (KERN_FAILURE);
+
 	MPASS(!map->system_map);
 
 	guard = stack_guard_page * PAGE_SIZE;