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posix: fix glob bugs with long login names 

Current glob implementation allows unlimited user name for home
directory construction on GLOB_TILDE case.  To accomplish it glob
either construct a name on stack if size are small enough (based
on current alloca_used) or in heap otherwise.

This patch simplifies storage allocation by using the same scratch
buffer for both get_rlogin_r and getpwnam_r.

This also syncs with gnulib commit 064df0b (glob: fix bugs with long
login names).

Checked on x86_64-linux-gnu and on a build using build-many-glibcs.py
for all major architectures.

	* posix/glob.c (GET_LOGIN_NAME_MAX): Remove.
	(glob): Use the same scratch buffer for both getlogin_r and
	getpwnam_r.  Don’t require preallocation of the login name.  This
	simplifies storage allocation, and corrects the handling of
	long login names.
This commit is contained in:
Adhemerval Zanella 2017-09-04 17:07:16 -03:00
parent 5a79f97554
commit ffca890177
2 changed files with 37 additions and 58 deletions
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7
ChangeLog
View File

@ -1,5 +1,12 @@
2017-09-08 Adhemerval Zanella <adhemerval.zanella@linaro.org> 2017-09-08 Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #1062]
* posix/glob.c (GET_LOGIN_NAME_MAX): Remove.
(glob): Use the same scratch buffer for both getlogin_r and
getpwnam_r. Don’t require preallocation of the login name. This
simplifies storage allocation, and corrects the handling of
long login names.
[BZ #1062] [BZ #1062]
* posix/glob.c (glob): Port recent patches to platforms * posix/glob.c (glob): Port recent patches to platforms
lacking getpwnam_r. lacking getpwnam_r.

88
posix/glob.c
View File

@ -75,12 +75,6 @@
#include <flexmember.h> #include <flexmember.h>
#include <glob_internal.h> #include <glob_internal.h>
#include <scratch_buffer.h> #include <scratch_buffer.h>
#ifdef _SC_LOGIN_NAME_MAX
# define GET_LOGIN_NAME_MAX() sysconf (_SC_LOGIN_NAME_MAX)
#else
# define GET_LOGIN_NAME_MAX() (-1)
#endif
static const char *next_brace_sub (const char *begin, int flags) __THROWNL; static const char *next_brace_sub (const char *begin, int flags) __THROWNL;
@ -610,67 +604,45 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
else else
home_dir = "c:/users/default"; /* poor default */ home_dir = "c:/users/default"; /* poor default */
#else #else
int success; int err;
char *name; struct passwd *p;
int malloc_name = 0; struct passwd pwbuf;
size_t buflen = GET_LOGIN_NAME_MAX () + 1; struct scratch_buffer s;
scratch_buffer_init (&s);
if (buflen == 0) while (true)
/* 'sysconf' does not support _SC_LOGIN_NAME_MAX. Try
a moderate value. */
buflen = 20;
if (glob_use_alloca (alloca_used, buflen))
name = alloca_account (buflen, alloca_used);
else
{ {
name = malloc (buflen); p = NULL;
if (name == NULL) err = __getlogin_r (s.data, s.length);
if (err == 0)
{
# if defined HAVE_GETPWNAM_R || defined _LIBC
size_t ssize = strlen (s.data) + 1;
err = getpwnam_r (s.data, &pwbuf, s.data + ssize,
s.length - ssize, &p);
# else
p = getpwnam (s.data);
if (p == NULL)
err = errno;
# endif
}
if (err != ERANGE)
break;
if (!scratch_buffer_grow (&s))
{ {
retval = GLOB_NOSPACE; retval = GLOB_NOSPACE;
goto out; goto out;
} }
malloc_name = 1;
} }
if (err == 0)
success = __getlogin_r (name, buflen) == 0;
if (success)
{ {
struct passwd *p; home_dir = strdup (p->pw_dir);
struct scratch_buffer pwtmpbuf; malloc_home_dir = 1;
scratch_buffer_init (&pwtmpbuf);
# if defined HAVE_GETPWNAM_R || defined _LIBC
struct passwd pwbuf;
while (getpwnam_r (name, &pwbuf,
pwtmpbuf.data, pwtmpbuf.length, &p)
== ERANGE)
{
if (!scratch_buffer_grow (&pwtmpbuf))
{
retval = GLOB_NOSPACE;
goto out;
}
}
# else
p = getpwnam (name);
# endif
if (p != NULL)
{
home_dir = strdup (p->pw_dir);
malloc_home_dir = 1;
if (home_dir == NULL)
{
scratch_buffer_free (&pwtmpbuf);
retval = GLOB_NOSPACE;
goto out;
}
}
scratch_buffer_free (&pwtmpbuf);
} }
else scratch_buffer_free (&s);
if (err == 0 && home_dir == NULL)
{ {
if (__glibc_unlikely (malloc_name)) retval = GLOB_NOSPACE;
free (name); goto out;
} }
#endif /* WINDOWS32 */ #endif /* WINDOWS32 */
} }