Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9fb1759a authored by Siddha, Suresh B's avatar Siddha, Suresh B Committed by Linus Torvalds
Browse files

[PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes 



A malicious 32bit app can have an elf section at 0xffffe000.  During
exec of this app, we will have a memory leak as insert_vm_struct() is
not checking for return value in syscall32_setup_pages() and thus not
freeing the vma allocated for the vsyscall page.

Check the return value and free the vma incase of failure.

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d6e18603

arch/x86_64/ia32/syscall32.c

+6 −1
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) 
	int npages = (VSYSCALL32_END - VSYSCALL32_BASE) >> PAGE_SHIFT;

	struct vm_area_struct *vma;

	struct mm_struct *mm = current->mm;

	int ret;



	vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);

	if (!vma)
@@ -78,7 +79,11 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) 
	vma->vm_mm = mm;



	down_write(&mm->mmap_sem);

	insert_vm_struct(mm, vma);

	if ((ret = insert_vm_struct(mm, vma))) {

		up_write(&mm->mmap_sem);

		kmem_cache_free(vm_area_cachep, vma);

		return ret;

	}

	mm->total_vm += npages;

	up_write(&mm->mmap_sem);

	return 0;