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 <puck.chen@xxxxxxxxxxxxx>
Signed-off-by: Wei Dong <weidong2@xxxxxxxxxxxxx>
Signed-off-by: Junmin Zhao <zhaojunmin@xxxxxxxxxx>
Reviewed-by: Zhuangluan Su <suzhuangluan@xxxxxxxxxxxxx>
---
drivers/android/binder.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index a39e85f..f080a8b 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);
--
1.9.1
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