[Bug libc/5939] mkostemp() strangeness

[Bug libc/5939] mkostemp() strangeness

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=5939

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Flags|                            |security-

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug libc/5939] New: mkostemp() strangeness

[mtk dot manpages at gmail dot com]

glibc 2.7 added mkostemp(), but with little information.  I'm trying to write
the man page for it, and I observe some strangeness:

mkostemp() calls __gen_tempname(), which contains the following code

  __gen_tempname (char *tmpl, int flags, int kind)
  {
   ...

          fd = __open (tmpl,
                       (flags & ~ACCESSPERMS)
                       | O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
          break;

The second argument of open() is the bitmask of O_* flags.  To mask this against
 ACCESSPERMS appears to be a thinko, since that constant is defined in
io/sys/stat.h as

# define ACCESSPERMS (S_IRWXU|S_IRWXG|S_IRWXO) /* 0777 */

Should the constant used in __gen_tempname() actually have been O_ACCMODE,
defined as

#define O_ACCMODE        0003

?

That would appear to be the case, given the definitions from <fcntl.h>

#define O_ACCMODE          0003
#define O_RDONLY             00
#define O_WRONLY             01
#define O_RDWR               02
#define O_CREAT            0100 /* not fcntl */
#define O_EXCL             0200 /* not fcntl */
#define O_NOCTTY           0400 /* not fcntl */
#define O_TRUNC           01000 /* not fcntl */
#define O_APPEND          02000
#define O_NONBLOCK        04000
#define O_NDELAY        O_NONBLOCK
#define O_SYNC           010000
#define O_FSYNC          O_SYNC
#define O_ASYNC          020000

#ifdef __USE_GNU
# define O_DIRECT        040000 /* Direct disk access.  */
# define O_DIRECTORY    0200000 /* Must be a directory.  */
# define O_NOFOLLOW     0400000 /* Do not follow links.  */
# define O_NOATIME     01000000 /* Do not set atime.  */
#endif

-- 
           Summary: mkostemp() strangeness
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: mtk dot manpages at gmail dot com
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=5939

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

[Bug libc/5939] mkostemp() strangeness

[drepper at redhat dot com]

------- Additional Comments From drepper at redhat dot com  2008-03-30 04:29 -------
Using O_ACCMODE is correct, I've changed the code.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=5939

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.