Re: [hackers] [sbase] [PATCH 5/5] mkdir: Fix created directory permissions

From: Silvan Jegen <s.jegen_AT_gmail.com>
Date: Thu, 15 Dec 2016 10:18:34 +0100

Hi

On Thu, Dec 15, 2016 at 4:40 AM, Michael Forney <mforney_AT_mforney.org> wrote:
> Previously, with -p, the specified directory and all of its parents
> would be 0777&~filemask (regardless of the -m flag). POSIX says parent
> directories must created as (0300|~filemask)&0777, and of course if -m
> is set, the specified directory should be created with those
> permissions.
>
> Additionally, POSIX says that for symbolic_mode strings, + and - should
> be interpretted relative to a default mode of 0777 (not 0).
>
> Without -p, previously the directory would be created first with
> 0777&~filemask (before a chmod), but POSIX says that the directory shall
> at no point in time have permissions less restrictive than the -m mode
> argument.
>
> Rather than dealing with mkdir removing the filemask bits by calling
> chmod afterward, just clear the umask and remove the bits manually.
> ---
> libutil/mkdirp.c | 6 +++---
> mkdir.c | 19 ++++++++-----------
> tar.c | 2 +-
> util.h | 2 +-
> 4 files changed, 13 insertions(+), 16 deletions(-)

I have stared at the patch for a while and it removes more lines than
it adds so I think this one is okay.

Note that I did not have time to test it though.


Cheers,

Silvan


> diff --git a/libutil/mkdirp.c b/libutil/mkdirp.c
> index 2ef94a3..c3c678c 100644
> --- a/libutil/mkdirp.c
> +++ b/libutil/mkdirp.c
> _AT_@ -7,7 +7,7 @@
> #include "../util.h"
>
> int
> -mkdirp(const char *path)
> +mkdirp(const char *path, mode_t mode, mode_t pmode)
> {
> char tmp[PATH_MAX], *p;
> struct stat st;
> _AT_@ -25,13 +25,13 @@ mkdirp(const char *path)
> if (*p != '/')
> continue;
> *p = '\0';
> - if (mkdir(tmp, S_IRWXU | S_IRWXG | S_IRWXO) < 0 && errno != EEXIST) {
> + if (mkdir(tmp, pmode) < 0 && errno != EEXIST) {
> weprintf("mkdir %s:", tmp);
> return -1;
> }
> *p = '/';
> }
> - if (mkdir(tmp, S_IRWXU | S_IRWXG | S_IRWXO) < 0 && errno != EEXIST) {
> + if (mkdir(tmp, mode) < 0 && errno != EEXIST) {
> weprintf("mkdir %s:", tmp);
> return -1;
> }
> diff --git a/mkdir.c b/mkdir.c
> index 3e32d90..3e20b1a 100644
> --- a/mkdir.c
> +++ b/mkdir.c
> _AT_@ -15,17 +15,18 @@ usage(void)
> int
> main(int argc, char *argv[])
> {
> - mode_t mode = 0, mask;
> - int pflag = 0, mflag = 0, ret = 0;
> + mode_t mode, mask;
> + int pflag = 0, ret = 0;
> +
> + mask = umask(0);
> + mode = 0777 & ~mask;
>
> ARGBEGIN {
> case 'p':
> pflag = 1;
> break;
> case 'm':
> - mflag = 1;
> - mask = getumask();
> - mode = parsemode(EARGF(usage()), mode, mask);
> + mode = parsemode(EARGF(usage()), 0777, mask);
> break;
> default:
> usage();
> _AT_@ -36,16 +37,12 @@ main(int argc, char *argv[])
>
> for (; *argv; argc--, argv++) {
> if (pflag) {
> - if (mkdirp(*argv) < 0)
> + if (mkdirp(*argv, mode, 0777 & (~mask | 0300)) < 0)
> ret = 1;
> - } else if (mkdir(*argv, S_IRWXU | S_IRWXG | S_IRWXO) < 0) {
> + } else if (mkdir(*argv, mode) < 0) {
> weprintf("mkdir %s:", *argv);
> ret = 1;
> }
> - if (mflag && chmod(*argv, mode) < 0) {
> - weprintf("chmod %s:", *argv);
> - ret = 1;
> - }
> }
>
> return ret;
> diff --git a/tar.c b/tar.c
> index d2161d4..f213039 100644
> --- a/tar.c
> +++ b/tar.c
> _AT_@ -262,7 +262,7 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
> weprintf("remove %s:", fname);
>
> tmp = estrdup(fname);
> - mkdirp(dirname(tmp));
> + mkdirp(dirname(tmp), 0777, 0777);
> free(tmp);
>
> switch (h->type) {
> diff --git a/util.h b/util.h
> index b5860dc..29325d2 100644
> --- a/util.h
> +++ b/util.h
> _AT_@ -75,6 +75,6 @@ long long strtonum(const char *, long long, long long, const char **);
> long long enstrtonum(int, const char *, long long, long long);
> long long estrtonum(const char *, long long, long long);
> size_t unescape(char *);
> -int mkdirp(const char *);
> +int mkdirp(const char *, mode_t, mode_t);
> #undef memmem
> void *memmem(const void *, size_t, const void *, size_t);
> --
> 2.11.0
>
>
Received on Thu Dec 15 2016 - 10:18:34 CET