答复: [PATCH] restorecond: Fix redundant console log output error

[kongbaichuan <kongbaichuan@huawei.com>]

The situation in policycoreutils/setfiles is different with restorecond. 
Two same-name varibales r_opts in policycoreutils/setfiles is not effected with each other, 
so it is not necessary to fix. 


-----邮件原件-----
发件人: Stephen Smalley [mailto:sds@tycho.nsa.gov] 
发送时间: 2019年11月12日 23:55
收件人: kongbaichuan <kongbaichuan@huawei.com>; selinux@vger.kernel.org
主题: Re: [PATCH] restorecond: Fix redundant console log output error

On 11/12/19 10:47 AM, Stephen Smalley wrote:
> On 11/11/19 8:23 PM, Baichuan Kong wrote:
>> From: kong baichuan <kongbaichuan@huawei.com>
>>
>> When starting restorecond without any option the following redundant 
>> console log is outputed:
>>
>> /dev/log 100.0%
>> /var/volatile/run/syslogd.pid 100.0%
>> ...
>>
>> This is caused by two global variables of same name r_opts. When 
>> executes r_opts = opts in restore_init(), it originally intends to 
>> assign the address of struct r_opts in "restorecond.c" to the pointer 
>> *r_opts in "restore.c".
>>
>> However, the address is assigned to the struct r_opts and covers the 
>> value of low eight bytes in it. That causes unexpected value of 
>> member varibale 'nochange' and 'verbose' in struct r_opts, thus 
>> affects value of 'restorecon_flags' and executes unexpected 
>> operations when restorecon the files such as the redundant console 
>> log output or file label nochange.
>>
>> Signed-off-by: kong baichuan <kongbaichuan@huawei.com>
> 
> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>

NB restore.c in restorecond was copied from policycoreutils/setfiles, which shares this same pattern, except that the separate r_opts declaration in setfiles.c is static.  We should likely fix it for setfiles as well.

> 
>> ---
>>   restorecond/restore.c | 40 ++++++++++++++++++----------------------
>>   1 file changed, 18 insertions(+), 22 deletions(-)
>>
>> diff --git a/restorecond/restore.c b/restorecond/restore.c
>> index f6e30001..b93b5fdb 100644
>> --- a/restorecond/restore.c
>> +++ b/restorecond/restore.c
>> @@ -12,39 +12,36 @@
>>   char **exclude_list;
>>   int exclude_count;
>> -struct restore_opts *r_opts;
>> -
>>   void restore_init(struct restore_opts *opts)
>>   {
>>       int rc;
>> -    r_opts = opts;
>>       struct selinux_opt selinux_opts[] = {
>> -        { SELABEL_OPT_VALIDATE, r_opts->selabel_opt_validate },
>> -        { SELABEL_OPT_PATH, r_opts->selabel_opt_path },
>> -        { SELABEL_OPT_DIGEST, r_opts->selabel_opt_digest }
>> +        { SELABEL_OPT_VALIDATE, opts->selabel_opt_validate },
>> +        { SELABEL_OPT_PATH, opts->selabel_opt_path },
>> +        { SELABEL_OPT_DIGEST, opts->selabel_opt_digest }
>>       };
>> -    r_opts->hnd = selabel_open(SELABEL_CTX_FILE, selinux_opts, 3);
>> -    if (!r_opts->hnd) {
>> -        perror(r_opts->selabel_opt_path);
>> +    opts->hnd = selabel_open(SELABEL_CTX_FILE, selinux_opts, 3);
>> +    if (!opts->hnd) {
>> +        perror(opts->selabel_opt_path);
>>           exit(1);
>>       }
>> -    r_opts->restorecon_flags = 0;
>> -    r_opts->restorecon_flags = r_opts->nochange | r_opts->verbose |
>> -               r_opts->progress | r_opts->set_specctx  |
>> -               r_opts->add_assoc | r_opts->ignore_digest |
>> -               r_opts->recurse | r_opts->userealpath |
>> -               r_opts->xdev | r_opts->abort_on_error |
>> -               r_opts->syslog_changes | r_opts->log_matches |
>> -               r_opts->ignore_noent | r_opts->ignore_mounts;
>> +    opts->restorecon_flags = 0;
>> +    opts->restorecon_flags = opts->nochange | opts->verbose |
>> +               opts->progress | opts->set_specctx  |
>> +               opts->add_assoc | opts->ignore_digest |
>> +               opts->recurse | opts->userealpath |
>> +               opts->xdev | opts->abort_on_error |
>> +               opts->syslog_changes | opts->log_matches |
>> +               opts->ignore_noent | opts->ignore_mounts;
>>       /* Use setfiles, restorecon and restorecond own handles */
>> -    selinux_restorecon_set_sehandle(r_opts->hnd);
>> +    selinux_restorecon_set_sehandle(opts->hnd);
>> -    if (r_opts->rootpath) {
>> -        rc = selinux_restorecon_set_alt_rootpath(r_opts->rootpath);
>> +    if (opts->rootpath) {
>> +        rc = selinux_restorecon_set_alt_rootpath(opts->rootpath);
>>           if (rc) {
>>               fprintf(stderr,
>>                   "selinux_restorecon_set_alt_rootpath error: %s.\n",
>> @@ -75,7 +72,6 @@ int process_glob(char *name, struct restore_opts *opts)
>>       size_t i = 0;
>>       int len, rc, errors;
>> -    r_opts = opts;
>>       memset(&globbuf, 0, sizeof(globbuf));
>>       errors = glob(name, GLOB_TILDE | GLOB_PERIOD |
>> @@ -90,7 +86,7 @@ int process_glob(char *name, struct restore_opts *opts)
>>           if (len > 0 && strcmp(&globbuf.gl_pathv[i][len], "/..") == 0)
>>               continue;
>>           rc = selinux_restorecon(globbuf.gl_pathv[i],
>> -                    r_opts->restorecon_flags);
>> +                    opts->restorecon_flags);
>>           if (rc < 0)
>>               errors = rc;
>>       }
>>
>