From 2fd4ef85e0db9ed75c98e13953257a967ea55e03 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 14 Sep 2005 06:13:02 +0100 Subject: [PATCH] error path in setup_arg_pages() misses vm_unacct_memory() Pavel Emelianov and Kirill Korotaev observe that fs and arch users of security_vm_enough_memory tend to forget to vm_unacct_memory when a failure occurs further down (typically in setup_arg_pages variants). These are all users of insert_vm_struct, and that reservation will only be unaccounted on exit if the vma is marked VM_ACCOUNT: which in some cases it is (hidden inside VM_STACK_FLAGS) and in some cases it isn't. So x86_64 32-bit and ppc64 vDSO ELFs have been leaking memory into Committed_AS each time they're run. But don't add VM_ACCOUNT to them, it's inappropriate to reserve against the very unlikely case that gdb be used to COW a vDSO page - we ought to do something about that in do_wp_page, but there are yet other inconsistencies to be resolved. The safe and economical way to fix this is to let insert_vm_struct do the security_vm_enough_memory check when it finds VM_ACCOUNT is set. And the MIPS irix_brk has been calling security_vm_enough_memory before calling do_brk which repeats it, doubly accounting and so also leaking. Remove that, and all the fs and arch calls to security_vm_enough_memory: give it a less misleading name later on. Signed-off-by: Hugh Dickins Signed-Off-By: Kirill Korotaev Signed-off-by: Linus Torvalds --- mm/mmap.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm') diff --git a/mm/mmap.c b/mm/mmap.c index 12334aecf8a..8b8e05f07cd 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1993,6 +1993,9 @@ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) __vma = find_vma_prepare(mm,vma->vm_start,&prev,&rb_link,&rb_parent); if (__vma && __vma->vm_start < vma->vm_end) return -ENOMEM; + if ((vma->vm_flags & VM_ACCOUNT) && + security_vm_enough_memory(vma_pages(vma))) + return -ENOMEM; vma_link(mm, vma, prev, rb_link, rb_parent); return 0; } -- cgit