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| author | Florian Weimer <fweimer@redhat.com> | 2015-10-02 11:34:13 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2015-10-02 11:34:13 +0200 |
| commit | 676599b36a92f3c201c5682ee7a5caddd9f370a4 (patch) | |
| tree | 6860752c26ccab76ee9db5e60ff465d1edf25feb /shadow/putspent.c | |
| parent | b0f81637d5bda47be93bac34b68f429a12979321 (diff) | |
| download | glibc-676599b36a92f3c201c5682ee7a5caddd9f370a4.zip glibc-676599b36a92f3c201c5682ee7a5caddd9f370a4.tar.gz glibc-676599b36a92f3c201c5682ee7a5caddd9f370a4.tar.bz2 | |
Harden putpwent, putgrent, putspent, putspent against injection [BZ #18724]
This prevents injection of ':' and '\n' into output functions which
use the NSS files database syntax. Critical fields (user/group names
and file system paths) are checked strictly. For backwards
compatibility, the GECOS field is rewritten instead.
The getent program is adjusted to use the put*ent functions in libc,
instead of local copies. This changes the behavior of getent if user
names start with '-' or '+'.
Diffstat (limited to 'shadow/putspent.c')
| -rw-r--r-- | shadow/putspent.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/shadow/putspent.c b/shadow/putspent.c index 142e697..ba8230a 100644 --- a/shadow/putspent.c +++ b/shadow/putspent.c @@ -15,6 +15,8 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <errno.h> +#include <nss.h> #include <stdio.h> #include <shadow.h> @@ -31,6 +33,13 @@ putspent (const struct spwd *p, FILE *stream) { int errors = 0; + if (p->sp_namp == NULL || !__nss_valid_field (p->sp_namp) + || !__nss_valid_field (p->sp_pwdp)) + { + __set_errno (EINVAL); + return -1; + } + flockfile (stream); if (fprintf (stream, "%s:%s:", p->sp_namp, _S (p->sp_pwdp)) < 0) |