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author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-09-04 17:07:16 -0300 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2017-09-08 16:33:39 +0200 |
commit | ffca890177bbf0980b66bc3a6d4d25c481957348 (patch) | |
tree | d8089db57032126b04c27cee659c90e0eea7e995 /posix | |
parent | 5a79f97554af6f2eb0a654f844b3d1f56937064d (diff) | |
download | glibc-ffca890177bbf0980b66bc3a6d4d25c481957348.zip glibc-ffca890177bbf0980b66bc3a6d4d25c481957348.tar.gz glibc-ffca890177bbf0980b66bc3a6d4d25c481957348.tar.bz2 |
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.
Diffstat (limited to 'posix')
-rw-r--r-- | posix/glob.c | 88 |
1 files changed, 30 insertions, 58 deletions
diff --git a/posix/glob.c b/posix/glob.c index ef620a1..a47507a 100644 --- a/posix/glob.c +++ b/posix/glob.c @@ -75,12 +75,6 @@ #include <flexmember.h> #include <glob_internal.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; @@ -610,67 +604,45 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int), else home_dir = "c:/users/default"; /* poor default */ #else - int success; - char *name; - int malloc_name = 0; - size_t buflen = GET_LOGIN_NAME_MAX () + 1; - - if (buflen == 0) - /* '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 + int err; + struct passwd *p; + struct passwd pwbuf; + struct scratch_buffer s; + scratch_buffer_init (&s); + while (true) { - name = malloc (buflen); - if (name == NULL) + p = NULL; + err = __getlogin_r (s.data, s.length); + if (err == 0) { - retval = GLOB_NOSPACE; - goto out; - } - malloc_name = 1; - } - - success = __getlogin_r (name, buflen) == 0; - if (success) - { - struct passwd *p; - struct scratch_buffer pwtmpbuf; - 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; - } - } + size_t ssize = strlen (s.data) + 1; + err = getpwnam_r (s.data, &pwbuf, s.data + ssize, + s.length - ssize, &p); # else - p = getpwnam (name); + p = getpwnam (s.data); + if (p == NULL) + err = errno; # endif - if (p != NULL) + } + if (err != ERANGE) + break; + if (!scratch_buffer_grow (&s)) { - home_dir = strdup (p->pw_dir); - malloc_home_dir = 1; - if (home_dir == NULL) - { - scratch_buffer_free (&pwtmpbuf); - retval = GLOB_NOSPACE; - goto out; - } + retval = GLOB_NOSPACE; + goto out; } - scratch_buffer_free (&pwtmpbuf); } - else + if (err == 0) + { + home_dir = strdup (p->pw_dir); + malloc_home_dir = 1; + } + scratch_buffer_free (&s); + if (err == 0 && home_dir == NULL) { - if (__glibc_unlikely (malloc_name)) - free (name); + retval = GLOB_NOSPACE; + goto out; } #endif /* WINDOWS32 */ } |