Re: [PATCH 1/7] binder: fix alloc->vma_vm_mm null-ptr dereference

From: Andrew Morton
Date: Mon Aug 29 2022 - 16:35:02 EST


On Mon, 29 Aug 2022 20:12:48 +0000 Carlos Llamas <cmllamas@xxxxxxxxxx> wrote:

> Syzbot reported a couple issues introduced by commit 44e602b4e52f
> ("binder_alloc: add missing mmap_lock calls when using the VMA"), in
> which we attempt to acquire the mmap_lock when alloc->vma_vm_mm has not
> been initialized yet.
>
> This can happen if a binder_proc receives a transaction without having
> previously called mmap() to setup the binder_proc->alloc space in [1].
> Also, a similar issue occurs via binder_alloc_print_pages() when we try
> to dump the debugfs binder stats file in [2].

Thanks. I assume you'll be merging all these into mainline?

>
> Fixes: 44e602b4e52f ("binder_alloc: add missing mmap_lock calls when using the VMA")
> Reported-by: syzbot+f7dc54e5be28950ac459@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-by: syzbot+a75ebe0452711c9e56d9@xxxxxxxxxxxxxxxxxxxxxxxxx
> Cc: <stable@xxxxxxxxxxxxxxx> # v5.15+

44e602b4e52f is only present in 6.0-rcX?