Re: [PATCH v10 07/11] LSM: Helpers for attribute names and filling lsm_ctx

Re: [PATCH v10 07/11] LSM: Helpers for attribute names and filling lsm_ctx

[kernel test robot]

Hi Casey,

kernel test robot noticed the following build errors:

[auto build test ERROR on tip/perf/core]
[also build test ERROR on acme/perf/core shuah-kselftest/next shuah-kselftest/fixes v6.3]
[cannot apply to linus/master next-20230428]
[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/Casey-Schaufler/LSM-Maintain-a-table-of-LSM-attribute-data/20230429-053458
base:   tip/perf/core
patch link:    https://lore.kernel.org/r/20230428203417.159874-8-casey%40schaufler-ca.com
patch subject: [PATCH v10 07/11] LSM: Helpers for attribute names and filling lsm_ctx
config: riscv-randconfig-r003-20230428 (https://download.01.org/0day-ci/archive/20230429/202304291044.WjF3wC86-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 437b7602e4a998220871de78afcb020b9c14a661)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/9830f4776196e33bee604b8ce3339177f8fd37f8
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Casey-Schaufler/LSM-Maintain-a-table-of-LSM-attribute-data/20230429-053458
        git checkout 9830f4776196e33bee604b8ce3339177f8fd37f8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv prepare

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304291044.WjF3wC86-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/riscv/kernel/asm-offsets.c:12:
   In file included from arch/riscv/include/asm/kvm_host.h:21:
   In file included from arch/riscv/include/asm/kvm_vcpu_pmu.h:12:
   In file included from include/linux/perf/riscv_pmu.h:12:
   In file included from include/linux/perf_event.h:62:
>> include/linux/security.h:516:9: error: use of undeclared identifier 'LSM_ATTR_UNDEF'
           return LSM_ATTR_UNDEF;
                  ^
   1 error generated.
   make[2]: *** [scripts/Makefile.build:114: arch/riscv/kernel/asm-offsets.s] Error 1
   make[2]: Target 'prepare' not remade because of errors.
   make[1]: *** [Makefile:1286: prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:226: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +/LSM_ATTR_UNDEF +516 include/linux/security.h

   513	
   514	static inline u64 lsm_name_to_attr(const char *name)
   515	{
 > 516		return LSM_ATTR_UNDEF;
   517	}
   518	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH v10 7/11] LSM: Helpers for attribute names and filling lsm_ctx

[Paul Moore]

On Apr 28, 2023 kernel test robot <lkp@intel.com> wrote:
> 
> Add lsm_name_to_attr(), which translates a text string to a
> LSM_ATTR value if one is available.
> 
> Add lsm_fill_user_ctx(), which fills a struct lsm_ctx, including
> the trailing attribute value. The .len value is padded to a multiple
> of 64 bits for alignment.
> 
> All are used in module specific components of LSM system calls.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>  include/linux/security.h | 13 ++++++++++++
>  security/lsm_syscalls.c  | 24 ++++++++++++++++++++++
>  security/security.c      | 44 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 81 insertions(+)

...

> diff --git a/security/security.c b/security/security.c
> index 94b78bfd06b9..8c877d639cae 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -761,6 +761,50 @@ static int lsm_superblock_alloc(struct super_block *sb)
>  	return 0;
>  }
>  
> +/**
> + * lsm_fill_user_ctx - Fill a user space lsm_ctx structure
> + * @ctx: an LSM context to be filled
> + * @context: the new context value
> + * @context_size: the size of the new context value
> + * @id: LSM id
> + * @flags: LSM defined flags
> + *
> + * Fill all of the fields in a user space lsm_ctx structure.
> + * Caller is assumed to have verified that @ctx has enough space
> + * for @context.
> + *
> + * The total length is padded to a multiple of 64 bits to
> + * accomodate possible alignment issues.
> + *
> + * Returns 0 on success, -EFAULT on a copyout error, -ENOMEM
> + * if memory can't be allocated.
> + */
> +int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
> +		      size_t context_size, u64 id, u64 flags)
> +{
> +	struct lsm_ctx *lctx;
> +	size_t locallen = ALIGN(struct_size(lctx, ctx, context_size), 8);

See my comment in 7/11 regarding the alignment calculation here.

> +	int rc = 0;
> +
> +	lctx = kzalloc(locallen, GFP_KERNEL);
> +	if (lctx == NULL)
> +		return -ENOMEM;
> +
> +	lctx->id = id;
> +	lctx->flags = flags;
> +	lctx->ctx_len = context_size;
> +	lctx->len = locallen;
> +
> +	memcpy(lctx->ctx, context, context_size);
> +
> +	if (copy_to_user(ctx, lctx, locallen))
> +		rc = -EFAULT;
> +
> +	kfree(lctx);
> +
> +	return rc;
> +}
> +
>  /*
>   * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
>   * can be accessed with:
> -- 
> 2.39.2

--
paul-moore.com