Disable -logfile and -modulepath when running with elevated privileges

Could cause privilege elevation and/or arbitrary files overwrite, when
the X server is running with elevated privileges (ie when Xorg is
installed with the setuid bit set and started by a non-root user).

CVE-2018-14665

Issue reported by Narendra Shinde and Red Hat.

Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Adam Jackson <ajax@redhat.com>
(cherry picked from commit 50c0cf885a)
This commit is contained in:
Matthieu Herrb 2018-10-23 21:29:08 +02:00 committed by Adam Jackson
parent cfc3dec09e
commit 8a59e3b7db
1 changed files with 6 additions and 2 deletions

View File

@ -1027,14 +1027,18 @@ ddxProcessArgument(int argc, char **argv, int i)
/* First the options that are not allowed with elevated privileges */
if (!strcmp(argv[i], "-modulepath")) {
CHECK_FOR_REQUIRED_ARGUMENT();
xf86CheckPrivs(argv[i], argv[i + 1]);
if (xf86PrivsElevated())
FatalError("\nInvalid argument -modulepath "
"with elevated privileges\n");
xf86ModulePath = argv[i + 1];
xf86ModPathFrom = X_CMDLINE;
return 2;
}
if (!strcmp(argv[i], "-logfile")) {
CHECK_FOR_REQUIRED_ARGUMENT();
xf86CheckPrivs(argv[i], argv[i + 1]);
if (xf86PrivsElevated())
FatalError("\nInvalid argument -logfile "
"with elevated privileges\n");
xf86LogFile = argv[i + 1];
xf86LogFileFrom = X_CMDLINE;
return 2;