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author | Hugh Dickins <hugh@veritas.com> | 2005-09-14 05:13:02 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-14 18:18:13 (GMT) |
commit | 2fd4ef85e0db9ed75c98e13953257a967ea55e03 (patch) | |
tree | 119dfe9f88a832f3db6ff66e631112626f268f18 /mm | |
parent | fb085cf1d4294824571815d487daccc0609543f0 (diff) | |
download | linux-2fd4ef85e0db9ed75c98e13953257a967ea55e03.tar.xz |
[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 <hugh@veritas.com>
Signed-Off-By: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/mmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -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; } |