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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
parentfb085cf1d4294824571815d487daccc0609543f0 (diff)
[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>
-rw-r--r--arch/ia64/ia32/binfmt_elf32.c6
-rw-r--r--arch/mips/kernel/sysirix.c9
-rw-r--r--arch/ppc64/kernel/vdso.c15
-rw-r--r--arch/x86_64/ia32/ia32_binfmt.c5
-rw-r--r--arch/x86_64/ia32/syscall32.c6
-rw-r--r--fs/exec.c5
-rw-r--r--mm/mmap.c3
7 files changed, 15 insertions, 34 deletions
diff --git a/arch/ia64/ia32/binfmt_elf32.c b/arch/ia64/ia32/binfmt_elf32.c
index 31de70b7c67f..a7280d9f6c16 100644
--- a/arch/ia64/ia32/binfmt_elf32.c
+++ b/arch/ia64/ia32/binfmt_elf32.c
@@ -216,12 +216,6 @@ ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
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));
down_write(&current->mm->mmap_sem);
diff --git a/arch/mips/kernel/sysirix.c b/arch/mips/kernel/sysirix.c
index 4de155699c4f..7ae4af476974 100644
--- a/arch/mips/kernel/sysirix.c
+++ b/arch/mips/kernel/sysirix.c
@@ -581,18 +581,13 @@ asmlinkage int irix_brk(unsigned long brk)
}
/*
- * Check if we have enough memory..
+ * Ok, looks good - let it rip.
*/
- if (security_vm_enough_memory((newbrk-oldbrk) >> PAGE_SHIFT)) {
+ if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk) {
ret = -ENOMEM;
goto out;
}
-
- /*
- * Ok, looks good - let it rip.
- */
mm->brk = brk;
- do_brk(oldbrk, newbrk-oldbrk);
ret = 0;
out:
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);
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;
diff --git a/fs/exec.c b/fs/exec.c
index 6fae59a22b43..a04a575ad433 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -421,11 +421,6 @@ int setup_arg_pages(struct linux_binprm *bprm,
if (!mpnt)
return -ENOMEM;
- if (security_vm_enough_memory(arg_size >> PAGE_SHIFT)) {
- kmem_cache_free(vm_area_cachep, mpnt);
- return -ENOMEM;
- }
-
memset(mpnt, 0, sizeof(*mpnt));
down_write(&mm->mmap_sem);
diff --git a/mm/mmap.c b/mm/mmap.c
index 12334aecf8ad..8b8e05f07cdb 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;
}