Re: [PATCH] libselinux: Strip spaces before values in config

[Vit Mojzis <vmojzis@xxxxxxxxxx>]

On 15. 01. 22 18:28, Christian Göttsche wrote:
> On Thu, 13 Jan 2022 at 21:44, Vit Mojzis <vmojzis@xxxxxxxxxx> wrote:
> > Spaces before values in /etc/selinux/config should be ignored just as
> > spaces after them are.
> >
> > E.g. "SELINUXTYPE= targeted" should be a valid value.
> >
> > Fixes:
> >     # sed -i 's/^SELINUXTYPE=/SELINUXTYPE= /g' /etc/selinux/config
> >     # dnf install <any_package>
> >     ...
> >     RPM: error: selabel_open: (/etc/selinux/ targeted/contexts/files/file_contexts) No such file or directory
> >     RPM: error: Plugin selinux: hook tsm_pre failed
> >     ...
> >     Error: Could not run transaction.
> >
> > Signed-off-by: Vit Mojzis <vmojzis@xxxxxxxxxx>
> > ---
> >   libselinux/src/selinux_config.c | 17 +++++++++++++----
> >   1 file changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/libselinux/src/selinux_config.c b/libselinux/src/selinux_config.c
> > index 97f81a8b..99cd6124 100644
> > --- a/libselinux/src/selinux_config.c
> > +++ b/libselinux/src/selinux_config.c
> > @@ -92,6 +92,7 @@ int selinux_getenforcemode(int *enforce)
> >          FILE *cfg = fopen(SELINUXCONFIG, "re");
> >          if (cfg) {
> >                  char *buf;
> > +               char *tag;
> >                  int len = sizeof(SELINUXTAG) - 1;
> >                  buf = malloc(selinux_page_size);
> >                  if (!buf) {
> > @@ -101,21 +102,24 @@ int selinux_getenforcemode(int *enforce)
> >                  while (fgets_unlocked(buf, selinux_page_size, cfg)) {
> >                          if (strncmp(buf, SELINUXTAG, len))
> >                                  continue;
> > +                       tag = buf+len;
> > +                       while (isspace(*tag))
> > +                               tag++;
> >                          if (!strncasecmp
> > -                           (buf + len, "enforcing", sizeof("enforcing") - 1)) {
> > +                           (tag, "enforcing", sizeof("enforcing") - 1)) {
> >                                  *enforce = 1;
> >                                  ret = 0;
> >                                  break;
> >                          } else
> >                              if (!strncasecmp
> > -                               (buf + len, "permissive",
> > +                               (tag, "permissive",
> >                                   sizeof("permissive") - 1)) {
> >                                  *enforce = 0;
> >                                  ret = 0;
> >                                  break;
> >                          } else
> >                              if (!strncasecmp
> > -                               (buf + len, "disabled",
> > +                               (tag, "disabled",
> >                                   sizeof("disabled") - 1)) {
> >                                  *enforce = -1;
> >                                  ret = 0;
> > @@ -176,7 +180,10 @@ static void init_selinux_config(void)
> >
> >                          if (!strncasecmp(buf_p, SELINUXTYPETAG,
> >                                           sizeof(SELINUXTYPETAG) - 1)) {
> > -                               type = strdup(buf_p + sizeof(SELINUXTYPETAG) - 1);
> > +                               buf_p += sizeof(SELINUXTYPETAG) - 1;
> > +                               while (isspace(*buf_p))
> > +                                       buf_p++;
> > +                               type = strdup(buf_p);
> >                                  if (!type) {
> >                                          free(line_buf);
> >                                          fclose(fp);
> > @@ -199,6 +206,8 @@ static void init_selinux_config(void)
> >                          } else if (!strncmp(buf_p, REQUIRESEUSERS,
> >                                              sizeof(REQUIRESEUSERS) - 1)) {
> >                                  value = buf_p + sizeof(REQUIRESEUSERS) - 1;
> > +                               while (isspace(*value))
> > +                                       buf_p++;
> This looks wrong.
Yes, sorry, stupid mistake.

> >                                  intptr = &require_seusers;
> >                          } else {
> >                                  continue;
> > --
> > 2.34.1