Re: [PATCH] tee: optee: ffa_abi: Fix use-after-free in optee_ffa_open

From: Jens Wiklander
Date: Tue Jan 03 2023 - 03:08:46 EST


Hi,

On Mon, Jan 2, 2023 at 1:17 AM Yoochan Lee <yoochan1026@xxxxxxxxx> wrote:
>
> I fix the error in the previous patch.
>
> From fde49d86f6401789ba51f267a0d79fbe4e7ffc24 Mon Sep 17 00:00:00 2001
> From: Yoochan Lee <yoochan1026@xxxxxxxxx>
> Date: Mon, 2 Jan 2023 09:16:05 +0900
> Subject: [PATCH 2/2] fix errors in previous patch
>
> ---
> drivers/tee/optee/ffa_abi.c | 17 ++++++-----------
> 1 file changed, 6 insertions(+), 11 deletions(-)

Please fix up the original patch and post it as a v2. By the way, have
you tried to test this in some way?

Thanks,
Jens

>
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index ea76d7532419..65d9463d9ed8 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -741,28 +741,23 @@ static void optee_ffa_delete(struct kref *kref)
>
> static void optee_ffa_release(struct tee_context *ctx)
> {
> - struct optee *optee = tee_get_drvdata(teedev);
> -
> - optee_release_helper(ctx, optee_close_session_helper);
> + struct optee *optee = tee_get_drvdata(ctx->teedev);
> +
> + optee_release(ctx);
> kref_put(&optee->refcnt, optee_ffa_delete);
> }
>
> void optee_ffa_release_supp(struct tee_context *ctx)
> {
> struct optee *optee = tee_get_drvdata(ctx->teedev);
> -
> - optee_release_helper(ctx, optee_close_session_helper);
> - if (optee->scan_bus_wq) {
> - destroy_workqueue(optee->scan_bus_wq);
> - optee->scan_bus_wq = NULL;
> - }
> - optee_supp_release(&optee->supp);
> +
> + optee_release_supp(ctx);
> kref_put(&optee->refcnt, optee_ffa_delete);
> }
>
> static int optee_ffa_open(struct tee_context *ctx)
> {
> - struct optee *optee = tee_get_drvdata(teedev);
> + struct optee *optee = tee_get_drvdata(ctx->teedev);
> kref_get(&optee->refcnt);
>
> return optee_open(ctx, true);
> --
> 2.39.0
>
> 2023년 1월 2일 (월) 오전 5:12, kernel test robot <lkp@xxxxxxxxx>님이 작성:
> >
> > Hi Yoochan,
> >
> > Thank you for the patch! Yet something to improve:
> >
> > [auto build test ERROR on linus/master]
> > [also build test ERROR on v6.2-rc1 next-20221226]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> >
> > url: https://github.com/intel-lab-lkp/linux/commits/Yoochan-Lee/tee-optee-ffa_abi-Fix-use-after-free-in-optee_ffa_open/20221231-133611
> > patch link: https://lore.kernel.org/r/20221231053421.2039591-1-yoochan1026%40gmail.com
> > patch subject: [PATCH] tee: optee: ffa_abi: Fix use-after-free in optee_ffa_open
> > config: arm-randconfig-c002-20221231
> > compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project f5700e7b69048de958172fb513b336564e7f8709)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install arm cross compiling tool for clang build
> > # apt-get install binutils-arm-linux-gnueabi
> > # https://github.com/intel-lab-lkp/linux/commit/3fe68a00d912f9e5dbec5002a7d30cf2a0868679
> > git remote add linux-review https://github.com/intel-lab-lkp/linux
> > git fetch --no-tags linux-review Yoochan-Lee/tee-optee-ffa_abi-Fix-use-after-free-in-optee_ffa_open/20221231-133611
> > git checkout 3fe68a00d912f9e5dbec5002a7d30cf2a0868679
> > # save the config file
> > mkdir build_dir && cp config build_dir/.config
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm olddefconfig
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/tee/optee/
> >
> > If you fix the issue, kindly add following tag where applicable
> > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >
> > All error/warnings (new ones prefixed by >>):
> >
> > >> drivers/tee/optee/ffa_abi.c:744:40: error: use of undeclared identifier 'teedev'
> > struct optee *optee = tee_get_drvdata(teedev);
> > ^
> > >> drivers/tee/optee/ffa_abi.c:746:2: error: call to undeclared function 'optee_release_helper'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> > optee_release_helper(ctx, optee_close_session_helper);
> > ^
> > drivers/tee/optee/ffa_abi.c:746:2: note: did you mean 'optee_release_supp'?
> > drivers/tee/optee/optee_private.h:258:6: note: 'optee_release_supp' declared here
> > void optee_release_supp(struct tee_context *ctx);
> > ^
> > drivers/tee/optee/ffa_abi.c:754:2: error: call to undeclared function 'optee_release_helper'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> > optee_release_helper(ctx, optee_close_session_helper);
> > ^
> > >> drivers/tee/optee/ffa_abi.c:750:6: warning: no previous prototype for function 'optee_ffa_release_supp' [-Wmissing-prototypes]
> > void optee_ffa_release_supp(struct tee_context *ctx)
> > ^
> > drivers/tee/optee/ffa_abi.c:750:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > void optee_ffa_release_supp(struct tee_context *ctx)
> > ^
> > static
> > drivers/tee/optee/ffa_abi.c:765:40: error: use of undeclared identifier 'teedev'
> > struct optee *optee = tee_get_drvdata(teedev);
> > ^
> > 1 warning and 4 errors generated.
> >
> >
> > vim +/teedev +744 drivers/tee/optee/ffa_abi.c
> >
> > 741
> > 742 static void optee_ffa_release(struct tee_context *ctx)
> > 743 {
> > > 744 struct optee *optee = tee_get_drvdata(teedev);
> > 745
> > > 746 optee_release_helper(ctx, optee_close_session_helper);
> > 747 kref_put(&optee->refcnt, optee_ffa_delete);
> > 748 }
> > 749
> > > 750 void optee_ffa_release_supp(struct tee_context *ctx)
> > 751 {
> > 752 struct optee *optee = tee_get_drvdata(ctx->teedev);
> > 753
> > 754 optee_release_helper(ctx, optee_close_session_helper);
> > 755 if (optee->scan_bus_wq) {
> > 756 destroy_workqueue(optee->scan_bus_wq);
> > 757 optee->scan_bus_wq = NULL;
> > 758 }
> > 759 optee_supp_release(&optee->supp);
> > 760 kref_put(&optee->refcnt, optee_ffa_delete);
> > 761 }
> > 762
> >
> > --
> > 0-DAY CI Kernel Test Service
> > https://01.org/lkp