Re: [PATCH 5.10 0/6] binder: backports for data leak and UAF

[Greg Kroah-Hartman]

On Wed, Nov 30, 2022 at 03:57:59AM +0000, Carlos Llamas wrote:
> This series of backports consists of 3 main patches from Todd submitted
> upstream in [1]. The intention is to avoid untranslated data from the
> senders to be visible to the target processes. More details of this
> issue can be found in the same thread.
> 
> Furthermore, Todd's patches also fix a use-after-free issue introduced
> by commit 32e9f56a96d8 ("binder: don't detect sender/target during
> buffer cleanup"). In which invalid userspace input causes unprocessed
> objects to be incorrectly released. Any subsequent references to these
> objects will trigger a UAF as noted by the following KASAN trace:
> 
>  [  244.748468] ==================================================================
>  [  244.750486] BUG: KASAN: use-after-free in binder_ioctl+0xb88/0x32e0
>  [  244.751276] Read of size 8 at addr ffff67b1865bea58 by task poc/593
>  [  244.752074] 
>  [  244.752725] CPU: 0 PID: 593 Comm: poc Not tainted 5.10.156 #1
>  [  244.753683] Hardware name: linux,dummy-virt (DT)
>  [  244.754717] Call trace:
>  [  244.755216]  dump_backtrace+0x0/0x2a0
>  [  244.755836]  show_stack+0x18/0x2c
>  [  244.756306]  dump_stack+0xf8/0x164
>  [  244.756807]  print_address_description.constprop.0+0x9c/0x538
>  [  244.757590]  kasan_report+0x120/0x200
>  [  244.758236]  __asan_load8+0xa0/0xc4
>  [  244.758756]  binder_ioctl+0xb88/0x32e0
>  [  244.759283]  __arm64_sys_ioctl+0xd4/0x120
>  [  244.759677]  el0_svc_common.constprop.0+0xac/0x270
>  [  244.760184]  do_el0_svc+0x38/0xa0
>  [  244.760540]  el0_svc+0x1c/0x2c
>  [  244.760898]  el0_sync_handler+0xe8/0x114
>  [  244.761419]  el0_sync+0x180/0x1c0
> 
> This second issue along with the reference to the commit fixing it was
> first reported by Zi Fan.
> 
> The other 3 commits included in this series are simply upstream fixes
> for the main patches.
> 
> I've tested this series applied to 5.10 and 5.4 which fixes the issues
> above as expected. So please pick these up for 5.10 and 5.4 stable.
> 
> [1] https://lore.kernel.org/all/20211130185152.437403-1-tkjos@xxxxxxxxxx/
> 
> Thanks,
> Carlos Llamas
> 
> Cc: Zi Fan Tan <zifantan@xxxxxxxxxx>
> Cc: Todd Kjos <tkjos@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> 

All now queued up, thanks.

greg k-h