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References: <20221231053421.2039591-1-yoochan1026@gmail.com> <202301020326.pzL5zDsa-lkp@intel.com>
In-Reply-To: <202301020326.pzL5zDsa-lkp@intel.com>
From:   Yoochan Lee <yoochan1026@gmail.com>
Date:   Mon, 2 Jan 2023 09:17:00 +0900
Message-ID: <CALQpDLcLghTY44YumjGj8McLsTUDkcxTKMOmjA5-oqEPGBG3ww@mail.gmail.com>
Subject: Re: [PATCH] tee: optee: ffa_abi: Fix use-after-free in optee_ffa_open
To:     kernel test robot <lkp@intel.com>
Cc:     jens.wiklander@linaro.org, llvm@lists.linux.dev,
        oe-kbuild-all@lists.linux.dev, op-tee@lists.trustedfirmware.org,
        linux-kernel@vger.kernel.org
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I fix the error in the previous patch.

From fde49d86f6401789ba51f267a0d79fbe4e7ffc24 Mon Sep 17 00:00:00 2001
From: Yoochan Lee <yoochan1026@gmail.com>
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(-)

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 =3D tee_get_drvdata(teedev);
-
- optee_release_helper(ctx, optee_close_session_helper);
+ struct optee *optee =3D 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 =3D 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 =3D 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 =3D tee_get_drvdata(teedev);
+ struct optee *optee =3D tee_get_drvdata(ctx->teedev);
  kref_get(&optee->refcnt);

  return optee_open(ctx, true);
--
2.39.0

2023=EB=85=84 1=EC=9B=94 2=EC=9D=BC (=EC=9B=94) =EC=98=A4=EC=A0=84 5:12, ke=
rnel test robot <lkp@intel.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> 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-op=
tee-ffa_abi-Fix-use-after-free-in-optee_ffa_open/20221231-133611
> patch link:    https://lore.kernel.org/r/20221231053421.2039591-1-yoochan=
1026%40gmail.com
> patch subject: [PATCH] tee: optee: ffa_abi: Fix use-after-free in optee_f=
fa_open
> config: arm-randconfig-c002-20221231
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project f570=
0e7b69048de958172fb513b336564e7f8709)
> reproduce (this is a W=3D1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbi=
n/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/3fe68a00d912f9e5d=
bec5002a7d30cf2a0868679
>         git remote add linux-review https://github.com/intel-lab-lkp/linu=
x
>         git fetch --no-tags linux-review Yoochan-Lee/tee-optee-ffa_abi-Fi=
x-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=3D$HOME/0day COMPILER=3Dclang make.cross W=
=3D1 O=3Dbuild_dir ARCH=3Darm olddefconfig
>         COMPILER_INSTALL_PATH=3D$HOME/0day COMPILER=3Dclang make.cross W=
=3D1 O=3Dbuild_dir ARCH=3Darm SHELL=3D/bin/bash drivers/tee/optee/
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@intel.com>
>
> All error/warnings (new ones prefixed by >>):
>
> >> drivers/tee/optee/ffa_abi.c:744:40: error: use of undeclared identifie=
r 'teedev'
>            struct optee *optee =3D 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_s=
upp'?
>    drivers/tee/optee/optee_private.h:258:6: note: 'optee_release_supp' de=
clared 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 funct=
ion 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 identifie=
r 'teedev'
>            struct optee *optee =3D 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 =3D 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 =3D 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 =3D 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