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authorHugh Dickins <hugh@veritas.com>2005-09-14 06:13:02 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-14 11:18:13 -0700
commit2fd4ef85e0db9ed75c98e13953257a967ea55e03 (patch)
tree119dfe9f88a832f3db6ff66e631112626f268f18 /arch/ppc64
parentfb085cf1d4294824571815d487daccc0609543f0 (diff)
downloadlinux-2fd4ef85e0db9ed75c98e13953257a967ea55e03.tar.bz2
[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 'arch/ppc64')
-rw-r--r--arch/ppc64/kernel/vdso.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/ppc64/kernel/vdso.c b/arch/ppc64/kernel/vdso.c
index 4777676365fe..efa985f05aca 100644
--- a/arch/ppc64/kernel/vdso.c
+++ b/arch/ppc64/kernel/vdso.c
@@ -224,10 +224,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack)
vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
if (vma == NULL)
return -ENOMEM;
- if (security_vm_enough_memory(vdso_pages)) {
- kmem_cache_free(vm_area_cachep, vma);
- return -ENOMEM;
- }
+
memset(vma, 0, sizeof(*vma));
/*
@@ -237,8 +234,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack)
*/
vdso_base = get_unmapped_area(NULL, vdso_base,
vdso_pages << PAGE_SHIFT, 0, 0);
- if (vdso_base & ~PAGE_MASK)
+ if (vdso_base & ~PAGE_MASK) {
+ kmem_cache_free(vm_area_cachep, vma);
return (int)vdso_base;
+ }
current->thread.vdso_base = vdso_base;
@@ -266,7 +265,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack)
vma->vm_ops = &vdso_vmops;
down_write(&mm->mmap_sem);
- insert_vm_struct(mm, vma);
+ if (insert_vm_struct(mm, vma)) {
+ up_write(&mm->mmap_sem);
+ kmem_cache_free(vm_area_cachep, vma);
+ return -ENOMEM;
+ }
mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
up_write(&mm->mmap_sem);