android: binder: fix dangling pointer comparison

If /dev/binder is opened and the opener process then e.g. calls execve,
proc->vma_vm_mm will still point to the location of the now-freed
mm_struct. If the process then calls ioctl(binder_fd, ...), the dangling
proc->vma_vm_mm pointer will be compared to current->mm.

Let the binder take a reference to the mm_struct to avoid this.

v2: use the right refcounter

Fixes: a906d6931f3c ("android: binder: Sanity check at binder ioctl")
Signed-off-by: Jann Horn <[email protected]>
Reviewed-by: Chen Feng <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions