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| author | Ruediger Meier <ruediger.meier@ga-group.nl> | 2017-06-27 20:33:08 +0200 |
|---|---|---|
| committer | Ruediger Meier <ruediger.meier@ga-group.nl> | 2017-06-29 14:03:49 +0200 |
| commit | f567220b716ee096cf6c094ab27dcdabaaa192f6 (patch) | |
| tree | 156828e9f82112b3d32d5074cd3612bc8862815e | |
| parent | e230ae7b68814a2ea560e5138188a58128e34417 (diff) | |
| download | util-linux-f567220b716ee096cf6c094ab27dcdabaaa192f6.tar.gz | |
lib/path: add error handling to path_vcreate()
Do not operate on truncated/random paths. Note, path_strdup()
can now really return NULL, to be handled in next commit.
Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
| -rw-r--r-- | lib/path.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/lib/path.c b/lib/path.c index eaa6d881c6..3c587e4333 100644 --- a/lib/path.c +++ b/lib/path.c @@ -38,11 +38,15 @@ static char pathbuf[PATH_MAX]; static const char * path_vcreate(const char *path, va_list ap) { - if (prefixlen) - vsnprintf(pathbuf + prefixlen, - sizeof(pathbuf) - prefixlen, path, ap); - else - vsnprintf(pathbuf, sizeof(pathbuf), path, ap); + int rc = vsnprintf( + pathbuf + prefixlen, sizeof(pathbuf) - prefixlen, path, ap); + + if (rc < 0) + return NULL; + if ((size_t)rc >= sizeof(pathbuf)) { + errno = ENAMETOOLONG; + return NULL; + } return pathbuf; } @@ -64,11 +68,18 @@ path_vfopen(const char *mode, int exit_on_error, const char *path, va_list ap) { FILE *f; const char *p = path_vcreate(path, ap); + if (!p) + goto err; f = fopen(p, mode); - if (!f && exit_on_error) - err(EXIT_FAILURE, _("cannot open %s"), p); + if (!f) + goto err; + return f; +err: + if (exit_on_error) + err(EXIT_FAILURE, _("cannot open %s"), p ? p : "path"); + return NULL; } static int @@ -76,11 +87,16 @@ path_vopen(int flags, const char *path, va_list ap) { int fd; const char *p = path_vcreate(path, ap); + if (!p) + goto err; fd = open(p, flags); if (fd == -1) - err(EXIT_FAILURE, _("cannot open %s"), p); + goto err; + return fd; +err: + err(EXIT_FAILURE, _("cannot open %s"), p ? p : "path"); } FILE * @@ -181,7 +197,7 @@ path_exist(const char *path, ...) p = path_vcreate(path, ap); va_end(ap); - return access(p, F_OK) == 0; + return p && access(p, F_OK) == 0; } #ifdef HAVE_CPU_SET_T |