From a906d6931f3ccaf7de805643190765ddd7378e27 Mon Sep 17 00:00:00 2001 From: Chen Feng Date: Mon, 1 Feb 2016 14:04:02 +0800 Subject: [PATCH] android: binder: Sanity check at binder ioctl Sanity check at binder ioctl function, Only allow the shared mm_struct to use the same binder-object to do binder operate. And add proc->vma_vm_mm = current->mm at the open function. The libbinder do ioctl before mmap called. V2: Fix compile error for error commit V3: Change the condition to proc->vma_vm_mm Signed-off-by: Chen Feng Signed-off-by: Wei Dong Signed-off-by: Junmin Zhao Reviewed-by: Zhuangluan Su Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index a39e85f9efa9..f080a8b7659b 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2737,6 +2737,10 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) /*pr_info("binder_ioctl: %d:%d %x %lx\n", proc->pid, current->pid, cmd, arg);*/ + if (unlikely(current->mm != proc->vma_vm_mm)) { + pr_err("current mm mismatch proc mm\n"); + return -EINVAL; + } trace_binder_ioctl(cmd, arg); ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); @@ -2951,6 +2955,7 @@ static int binder_open(struct inode *nodp, struct file *filp) return -ENOMEM; get_task_struct(current); proc->tsk = current; + proc->vma_vm_mm = current->mm; INIT_LIST_HEAD(&proc->todo); init_waitqueue_head(&proc->wait); proc->default_priority = task_nice(current);