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From:   Paul Moore <paul@paul-moore.com>
Date:   Wed, 8 Jul 2020 18:41:42 -0400
Message-ID: <CAHC9VhQT2O9GnVBhXvzpP+yNNoCqy-XTfMC7OHqz3xvFVaGvdw@mail.gmail.com>
Subject: Re: [PATCH ghak84 v3] audit: purge audit_log_string from the
 intra-kernel audit API
To:     Richard Guy Briggs <rgb@redhat.com>
Cc:     Linux-Audit Mailing List <linux-audit@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Security Module list 
        <linux-security-module@vger.kernel.org>,
        Eric Paris <eparis@parisplace.org>, john.johansen@canonical.com
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On Fri, Jul 3, 2020 at 5:50 PM Richard Guy Briggs <rgb@redhat.com> wrote:
>
> audit_log_string() was inteded to be an internal audit function and
> since there are only two internal uses, remove them.  Purge all external
> uses of it by restructuring code to use an existing audit_log_format()
> or using audit_log_format().
>
> Please see the upstream issue
> https://github.com/linux-audit/audit-kernel/issues/84
>
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
> Passes audit-testsuite.
>
> Changelog:
> v3
> - fix two warning: non-void function does not return a value in all control paths
>         Reported-by: kernel test robot <lkp@intel.com>
>
> v2
> - restructure to piggyback on existing audit_log_format() calls, checking quoting needs for each.
>
> v1 Vlad Dronov
> - https://github.com/nefigtut/audit-kernel/commit/dbbcba46335a002f44b05874153a85b9cc18aebf
>
>  include/linux/audit.h     |  5 -----
>  kernel/audit.c            |  4 ++--
>  security/apparmor/audit.c | 10 ++++------
>  security/apparmor/file.c  | 25 +++++++------------------
>  security/apparmor/ipc.c   | 46 +++++++++++++++++++++++-----------------------
>  security/apparmor/net.c   | 14 ++++++++------
>  security/lsm_audit.c      |  4 ++--
>  7 files changed, 46 insertions(+), 62 deletions(-)

...

> diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
> index 597732503815..335b5b8d300b 100644
> --- a/security/apparmor/audit.c
> +++ b/security/apparmor/audit.c
> @@ -57,18 +57,16 @@ static void audit_pre(struct audit_buffer *ab, void *ca)
>         struct common_audit_data *sa = ca;
>
>         if (aa_g_audit_header) {
> -               audit_log_format(ab, "apparmor=");
> -               audit_log_string(ab, aa_audit_type[aad(sa)->type]);
> +               audit_log_format(ab, "apparmor=%s",
> +                                aa_audit_type[aad(sa)->type]);
>         }
>
>         if (aad(sa)->op) {
> -               audit_log_format(ab, " operation=");
> -               audit_log_string(ab, aad(sa)->op);
> +               audit_log_format(ab, " operation=%s", aad(sa)->op);
>         }

In the case below you've added the quotes around the string, but they
appear to be missing in the two cases above.

>         if (aad(sa)->info) {
> -               audit_log_format(ab, " info=");
> -               audit_log_string(ab, aad(sa)->info);
> +               audit_log_format(ab, " info=\"%s\"", aad(sa)->info);
>                 if (aad(sa)->error)
>                         audit_log_format(ab, " error=%d", aad(sa)->error);
>         }
> diff --git a/security/apparmor/file.c b/security/apparmor/file.c
> index 9a2d14b7c9f8..70f27124d051 100644
> --- a/security/apparmor/file.c
> +++ b/security/apparmor/file.c
> @@ -35,20 +35,6 @@ static u32 map_mask_to_chr_mask(u32 mask)
>  }
>
>  /**
> - * audit_file_mask - convert mask to permission string
> - * @buffer: buffer to write string to (NOT NULL)
> - * @mask: permission mask to convert
> - */
> -static void audit_file_mask(struct audit_buffer *ab, u32 mask)
> -{
> -       char str[10];
> -
> -       aa_perm_mask_to_str(str, sizeof(str), aa_file_perm_chrs,
> -                           map_mask_to_chr_mask(mask));
> -       audit_log_string(ab, str);
> -}
> -
> -/**
>   * file_audit_cb - call back for file specific audit fields
>   * @ab: audit_buffer  (NOT NULL)
>   * @va: audit struct to audit values of  (NOT NULL)
> @@ -57,14 +43,17 @@ static void file_audit_cb(struct audit_buffer *ab, void *va)
>  {
>         struct common_audit_data *sa = va;
>         kuid_t fsuid = current_fsuid();
> +       char str[10];
>
>         if (aad(sa)->request & AA_AUDIT_FILE_MASK) {
> -               audit_log_format(ab, " requested_mask=");
> -               audit_file_mask(ab, aad(sa)->request);
> +               aa_perm_mask_to_str(str, sizeof(str), aa_file_perm_chrs,
> +                                   map_mask_to_chr_mask(aad(sa)->request));
> +               audit_log_format(ab, " requested_mask=%s", str);
>         }
>         if (aad(sa)->denied & AA_AUDIT_FILE_MASK) {
> -               audit_log_format(ab, " denied_mask=");
> -               audit_file_mask(ab, aad(sa)->denied);
> +               aa_perm_mask_to_str(str, sizeof(str), aa_file_perm_chrs,
> +                                   map_mask_to_chr_mask(aad(sa)->denied));
> +               audit_log_format(ab, " denied_mask=%s", str);
>         }

More missing quotes.

>         if (aad(sa)->request & AA_AUDIT_FILE_MASK) {
>                 audit_log_format(ab, " fsuid=%d",
> diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
> index 4ecedffbdd33..fe431731883f 100644
> --- a/security/apparmor/ipc.c
> +++ b/security/apparmor/ipc.c
> @@ -20,25 +20,23 @@
>
>  /**
>   * audit_ptrace_mask - convert mask to permission string
> - * @buffer: buffer to write string to (NOT NULL)
>   * @mask: permission mask to convert
> + *
> + * Returns: pointer to static string
>   */
> -static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
> +static const char *audit_ptrace_mask(u32 mask)
>  {
>         switch (mask) {
>         case MAY_READ:
> -               audit_log_string(ab, "read");
> -               break;
> +               return "read";
>         case MAY_WRITE:
> -               audit_log_string(ab, "trace");
> -               break;
> +               return "trace";
>         case AA_MAY_BE_READ:
> -               audit_log_string(ab, "readby");
> -               break;
> +               return "readby";
>         case AA_MAY_BE_TRACED:
> -               audit_log_string(ab, "tracedby");
> -               break;
> +               return "tracedby";
>         }
> +       return "";
>  }
>
>  /* call back to audit ptrace fields */
> @@ -47,12 +45,12 @@ static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
>         struct common_audit_data *sa = va;
>
>         if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
> -               audit_log_format(ab, " requested_mask=");
> -               audit_ptrace_mask(ab, aad(sa)->request);
> +               audit_log_format(ab, " requested_mask=%s",
> +                                audit_ptrace_mask(aad(sa)->request));
>
>                 if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
> -                       audit_log_format(ab, " denied_mask=");
> -                       audit_ptrace_mask(ab, aad(sa)->denied);
> +                       audit_log_format(ab, " denied_mask=%s",
> +                                        audit_ptrace_mask(aad(sa)->denied));
>                 }

Quotes.  There are none.

... and it looks like there are more missing too, but I kinda stopped
seriously reading the patch here, please take a closer look at the
patch, make the necessary changes, and resubmit.

-- 
paul moore
www.paul-moore.com