[wp-trac] [WordPress Trac] #31167: SSH2/SFTP newline breaks path causes segfault and "Save Changes" missing in UI

[WordPress Trac]

#31167: SSH2/SFTP newline breaks path causes segfault and "Save Changes" missing in
UI
----------------------------+-----------------------------
 Reporter:  thajekku        |      Owner:
     Type:  defect (bug)    |     Status:  new
 Priority:  normal          |  Milestone:  Awaiting Review
Component:  Administration  |    Version:  4.1
 Severity:  normal          |   Keywords:
  Focuses:  administration  |
----------------------------+-----------------------------
 Trying to use the SSH2 update method on 4.1.  Running on Red Hat
 Enterprise Linux 6.6 with php55 and httpd24 from SCL (software
 collections).

 After installing the php55-php-pecl-ssh2 I was getting segfaults from php-
 fpm causing "Service Unavailable" messages when performing certain
 functions such as trying to remove a plugin (installing a plugin however
 worked).
 I also noticed that I did not have the "Save Changes" submit button in
 Settings->General or anything underneath TimeZone.  TimeZone was simply
 showing "UTC+0".

 I worked through Red Hat support to rule out php-fpm as the cause and it
 appears that there is a newline being introduced in the pwd call in class-
 wp-filesystem-ssh2.php causing the issue.
 It makes the path /var/www/sites/wca/ turn into /var/www/sites/wca\n/.
 Part of the trace is below:
 {{{
         #0  __strlen_sse42 () at ../sysdeps/x86_64/multiarch/strlen-
 sse4.S:32
         #1  0x000000000058d4bf in _estrdup (s=0x0) at
 /usr/src/debug/php-5.5.6/Zend/zend_alloc.c:2630
         #2  0x00007fcb122aac76 in php_ssh2_fopen_wraper_parse_path
 (path=0x36ab5c8 "ssh2.sftp://Resource id #140/var/www/sites/wca\n/",
 type=<value optimized out>, context=0x0, psession=0x7fffe8cab9d0,
             presource_id=0x7fffe8cab9dc, psftp=0x7fffe8cab9c8,
 psftp_rsrcid=0x7fffe8cab9d8) at /usr/src/debug/php55-php-pecl-
 ssh2-0.12/NTS/ssh2_fopen_wrappers.c:226
         #3  0x00007fcb122ad626 in php_ssh2_sftp_urlstat (wrapper=<value
 optimized out>, url=<value optimized out>, flags=2, ssb=0x7fffe8cabad0,
 context=<value optimized out>)
             at /usr/src/debug/php55-php-pecl-ssh2-0.12/NTS/ssh2_sftp.c:390
         #4  0x000000000056a65f in _php_stream_stat_path (path=0x36ab5c8
 "ssh2.sftp://Resource id #140/var/www/sites/wca\n/", flags=2,
 ssb=0x7fffe8cabad0, context=0x0)
             at /usr/src/debug/php-5.5.6/main/streams/streams.c:1933
         #5  0x0000000000507a82 in php_stat (filename=0x36ab5c8
 "ssh2.sftp://Resource id #140/var/www/sites/wca\n/",
 filename_length=<value optimized out>, type=12, return_value=0x3a657f8)
             at /usr/src/debug/php-5.5.6/ext/standard/filestat.c:906
 }}}
 It appears that a simple fix might be to just rtrim the call to pwd in
 class-wp-filesystem-ssh2.php, at least that fixed the issues I am seeing
 (do not know if it introduces any).

 I changed the following function (just line 187) from:
 {{{
 186         public function cwd() {
 187                 $cwd = $this->run_command('pwd');
 188                 if ( $cwd )
 189                         $cwd = trailingslashit($cwd);
 190                 return $cwd;
 191         }
 }}}
 to
 {{{
 186         public function cwd() {
 187                 $cwd = rtrim($this->run_command('pwd'));
 188                 if ( $cwd )
 189                         $cwd = trailingslashit($cwd);
 190                 return $cwd;
 191         }
 }}}

 After making that change it appears that the SSH2 functions work properly.

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Ticket URL: <https://core.trac.wordpress.org/ticket/31167>
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