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 --- arch/x86_64/ia32/ia32_binfmt.c | 5 ----- arch/x86_64/ia32/syscall32.c | 6 +----- 2 files changed, 1 insertion(+), 10 deletions(-) (limited to 'arch/x86_64/ia32') diff --git a/arch/x86_64/ia32/ia32_binfmt.c b/arch/x86_64/ia32/ia32_binfmt.c index c8131f342cfc..d9161e395978 100644 --- a/arch/x86_64/ia32/ia32_binfmt.c +++ b/arch/x86_64/ia32/ia32_binfmt.c @@ -353,11 +353,6 @@ int setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int exec mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); if (!mpnt) return -ENOMEM; - - if (security_vm_enough_memory((IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) { - kmem_cache_free(vm_area_cachep, mpnt); - return -ENOMEM; - } memset(mpnt, 0, sizeof(*mpnt)); diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c index adbc5f8089e9..3a01329473ab 100644 --- a/arch/x86_64/ia32/syscall32.c +++ b/arch/x86_64/ia32/syscall32.c @@ -52,17 +52,13 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); if (!vma) return -ENOMEM; - if (security_vm_enough_memory(npages)) { - kmem_cache_free(vm_area_cachep, vma); - return -ENOMEM; - } memset(vma, 0, sizeof(struct vm_area_struct)); /* Could randomize here */ vma->vm_start = VSYSCALL32_BASE; vma->vm_end = VSYSCALL32_END; /* MAYWRITE to allow gdb to COW and set breakpoints */ - vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYEXEC|VM_MAYWRITE; + vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; vma->vm_flags |= mm->def_flags; vma->vm_page_prot = protection_map[vma->vm_flags & 7]; vma->vm_ops = &syscall32_vm_ops; -- cgit v1.2.1