From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH] conf: Fix one Coverity CID 258163 warning, work around another one Date: Fri, 20 May 2022 11:01:22 +0200 Message-ID: <20220520090122.2510632-1-sbrivio@redhat.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8435687225399799357==" --===============8435687225399799357== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable In conf_runas(), Coverity reports that we might dereference uid and gid despite possibly being NULL (CWE-476) because of the check after the first sscanf(). They can't be NULL, but I actually wanted to check that UID and GID are non-zero (the user could otherwise pass --runas root:root and defy the whole mechanism). Later on, we have the same type of warning for 'gr': it's compared against NULL, so it might be NULL, which is actually the case: but in that case, we don't dereference it, because we'll return -ENOENT right away. Rewrite the clause to silence the warning. Signed-off-by: Stefano Brivio --- conf.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/conf.c b/conf.c index ddad9a3..d615cf5 100644 --- a/conf.c +++ b/conf.c @@ -857,7 +857,7 @@ static int conf_runas(const char *opt, unsigned int *uid,= unsigned int *gid) struct group *gr; =20 /* NOLINTNEXTLINE(cert-err34-c): 2 if conversion succeeds */ - if (sscanf(opt, "%u:%u", uid, gid) =3D=3D 2 && uid && gid) + if (sscanf(opt, "%u:%u", uid, gid) =3D=3D 2 && *uid && *gid) return 0; =20 *uid =3D strtol(opt, &endptr, 0); @@ -874,12 +874,10 @@ static int conf_runas(const char *opt, unsigned int *ui= d, unsigned int *gid) /* NOLINTNEXTLINE(cert-err34-c): 2 if conversion succeeds */ if (sscanf(opt, "%" STR(LOGIN_NAME_MAX) "[^:]:" "%" STR(LOGIN_NAME_MAX) "s", ubuf, gbuf) =3D=3D 2) { - pw =3D getpwnam(ubuf); - if (!pw || !(*uid =3D pw->pw_uid)) + if (!(pw =3D getpwnam(ubuf)) || !(*uid =3D pw->pw_uid)) return -ENOENT; =20 - gr =3D getgrnam(gbuf); - if (!gr || !(*gid =3D gr->gr_gid)) + if (!(gr =3D getgrnam(gbuf)) || !(*gid =3D gr->gr_gid)) return -ENOENT; =20 return 0; --=20 2.35.1 --===============8435687225399799357==--