Message-ID: <5b334b57-3fcf-9cfa-7745-5f6895be9768@schaufler-ca.com>
Date:   Tue, 14 Feb 2023 10:06:09 -0800
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Subject: Re: [PATCH v5 4/8] LSM: lsm_get_self_attr syscall for LSM self
 attributes
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To:     =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= <mic@digikod.net>,
        casey.schaufler@intel.com, paul@paul-moore.com,
        linux-security-module@vger.kernel.org
Cc:     jmorris@namei.org, keescook@chromium.org,
        john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
        stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org,
        linux-api@vger.kernel.org, casey@schaufler-ca.com
References: <20230109180717.58855-1-casey@schaufler-ca.com>
 <20230109180717.58855-5-casey@schaufler-ca.com>
 <3977d478-cb41-832b-7b5e-73dd247f267d@digikod.net>
From:   Casey Schaufler <casey@schaufler-ca.com>
In-Reply-To: <3977d478-cb41-832b-7b5e-73dd247f267d@digikod.net>
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Precedence: bulk

On 2/14/2023 9:41 AM, Mickaël Salaün wrote:
>
> On 09/01/2023 19:07, Casey Schaufler wrote:
>> Create a system call lsm_get_self_attr() to provide the security
>> module maintained attributes of the current process. Historically
>> these attributes have been exposed to user space via entries in
>> procfs under /proc/self/attr.
>>
>> Attributes are provided as a collection of lsm_ctx structures
>> which are placed into a user supplied buffer. Each structure
>> identifys the size of the attribute, and the attribute value.
>> The format of the attribute value is defined by the security
>> module, but will always be \0 terminated. The ctx_len value
>> will always be strlen(ctx)+1.
>>
>>          ---------------------------
>>          | __u32 id                |
>>          ---------------------------
>>          | __u64 flags             |
>>          ---------------------------
>>          | __kernel_size_t ctx_len |
>>          ---------------------------
>>          | __u8 ctx[ctx_len]       |
>>          ---------------------------
>>          | __u32 id                |
>>          ---------------------------
>>          | __u64 flags             |
>>          ---------------------------
>>          | __kernel_size_t ctx_len |
>>          ---------------------------
>>          | __u8 ctx[ctx_len]       |
>>          ---------------------------
>>
>> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
>> ---
>>   Documentation/userspace-api/lsm.rst |   9 ++
>>   include/linux/syscalls.h            |   3 +
>>   include/uapi/linux/lsm.h            |  21 ++++
>>   kernel/sys_ni.c                     |   3 +
>>   security/Makefile                   |   1 +
>>   security/lsm_syscalls.c             | 182 ++++++++++++++++++++++++++++
>>   6 files changed, 219 insertions(+)
>>   create mode 100644 security/lsm_syscalls.c
>
> For new files (e.g. lsm_syscalls.c), it would be nice to auto-format
> them with clang-format. It helps maintenance by keeping a consistent
> style across commits, which should also help backports, and it avoids
> nitpicking on style issues.

Good idea.