--- configure.ac | 4 ++- hw/xfree86/common/xf86Config.c | 28 ++++++++-------- hw/xfree86/common/xf86Init.c | 68 ++++++++++++++++++++++++++++++++++----- hw/xfree86/common/xf86Priv.h | 1 + include/xorg-config.h.in | 6 +++ 5 files changed, 83 insertions(+), 24 deletions(-) diff --git a/configure.ac b/configure.ac index 67a6836..a79e2be 100644 --- a/configure.ac +++ b/configure.ac @@ -208,9 +208,11 @@ AC_SUBST(DLOPEN_LIBS) dnl Checks for library functions. AC_FUNC_VPRINTF -AC_CHECK_FUNCS([geteuid getuid link memmove memset mkstemp strchr strrchr \ +AC_CHECK_FUNCS([geteuid getuid issetugid getresuid \ + link memmove memset mkstemp strchr strrchr \ strtol getopt getopt_long vsnprintf walkcontext backtrace \ getisax getzoneid shmctl64 strcasestr ffs vasprintf]) + AC_FUNC_ALLOCA dnl Old HAS_* names used in os/*.c. AC_CHECK_FUNC([getdtablesize], diff --git a/hw/xfree86/common/xf86Config.c b/hw/xfree86/common/xf86Config.c index f8c1b65..8ccc52a 100644 --- a/hw/xfree86/common/xf86Config.c +++ b/hw/xfree86/common/xf86Config.c @@ -72,8 +72,8 @@ * These paths define the way the config file search is done. The escape * sequences are documented in parser/scan.c. */ -#ifndef ROOT_CONFIGPATH -#define ROOT_CONFIGPATH "%A," "%R," \ +#ifndef ALL_CONFIGPATH +#define ALL_CONFIGPATH "%A," "%R," \ "/etc/X11/%R," "%P/etc/X11/%R," \ "%E," "%F," \ "/etc/X11/%F," "%P/etc/X11/%F," \ @@ -83,8 +83,8 @@ "%P/lib/X11/%X.%H," \ "%P/lib/X11/%X" #endif -#ifndef USER_CONFIGPATH -#define USER_CONFIGPATH "/etc/X11/%S," "%P/etc/X11/%S," \ +#ifndef RESTRICTED_CONFIGPATH +#define RESTRICTED_CONFIGPATH "/etc/X11/%S," "%P/etc/X11/%S," \ "/etc/X11/%G," "%P/etc/X11/%G," \ "/etc/X11/%X," "/etc/%X," \ "%P/etc/X11/%X.%H," \ @@ -92,14 +92,14 @@ "%P/lib/X11/%X.%H," \ "%P/lib/X11/%X" #endif -#ifndef ROOT_CONFIGDIRPATH -#define ROOT_CONFIGDIRPATH "%A," "%R," \ +#ifndef ALL_CONFIGDIRPATH +#define ALL_CONFIGDIRPATH "%A," "%R," \ "/etc/X11/%R," "%C/X11/%R," \ "/etc/X11/%X," "%C/X11/%X" #endif -#ifndef USER_CONFIGDIRPATH -#define USER_CONFIGDIRPATH "/etc/X11/%R," "%C/X11/%R," \ - "/etc/X11/%X," "%C/X11/%X" +#ifndef RESTRICTED_CONFIGDIRPATH +#define RESTRICTED_CONFIGDIRPATH "/etc/X11/%R," "%C/X11/%R," \ + "/etc/X11/%X," "%C/X11/%X" #endif #ifndef SYS_CONFIGDIRPATH #define SYS_CONFIGDIRPATH "/usr/share/X11/%X," "%D/X11/%X" @@ -2302,12 +2302,12 @@ xf86HandleConfigFile(Bool autoconfig) Bool implicit_layout = FALSE; if (!autoconfig) { - if (getuid() == 0) { - filesearch = ROOT_CONFIGPATH; - dirsearch = ROOT_CONFIGDIRPATH; + if (!xf86PrivsElevated()) { + filesearch = ALL_CONFIGPATH; + dirsearch = ALL_CONFIGDIRPATH; } else { - filesearch = USER_CONFIGPATH; - dirsearch = USER_CONFIGDIRPATH; + filesearch = RESTRICTED_CONFIGPATH; + dirsearch = RESTRICTED_CONFIGDIRPATH; } if (xf86ConfigFile) diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c index 350918d..063a2d8 100644 --- a/hw/xfree86/common/xf86Init.c +++ b/hw/xfree86/common/xf86Init.c @@ -237,6 +237,55 @@ xf86PrintMarkers(void) LogPrintMarkers(); } +Bool xf86PrivsElevated(void) +{ + static Bool privsTested = FALSE; + static Bool privsElevated = FALSE; + + if (!privsTested) { +#if !defined(WIN32) + if ((getuid() != geteuid()) || (getgid() != getegid())) { + privsElevated = TRUE; + } else { +#if defined(HAVE_ISSETUGID) + privsElevated = issetugid(); +#elif defined(HAVE_GETRESUID) + uid_t ruid, euid, suid; + gid_t rgid, egid, sgid; + + if ((getresuid(&ruid, &euid, &suid) == 0) && + (getresgid(&rgid, &egid, &sgid) == 0)) + privsElevated = (euid != suid) || (egid != sgid); +#else + /* + * If there are saved ID's the process might still be privileged + * even though the above test succeeded. If issetugid() and + * getresgid() aren't available, test this by trying to set + * euid to 0. + */ + unsigned int oldeuid; + oldeuid = geteuid(); + + if (seteuid(0) != 0) { + privsElevated = FALSE; + } else { + if (seteuid(oldeuid) != 0) { + /* XXX ouch, coudn't get back to original uid + what can we do ??? */ + fprintf("failed to drop privileges after elevating them!\n" + "cannot continue safely, terminating"); + exit(127); + } + privsElevated = TRUE; + } +#endif + } +#endif + privsTested = TRUE; + } + return privsElevated; +} + static Bool xf86CreateRootWindow(WindowPtr pWin) { @@ -896,7 +945,7 @@ OsVendorInit(void) #ifdef O_NONBLOCK if (!beenHere) { - if (geteuid() == 0 && getuid() != geteuid()) + if (xf86PrivsElevated()) { int status; @@ -1067,10 +1116,11 @@ ddxProcessArgument(int argc, char **argv, int i) FatalError("Required argument to %s not specified\n", argv[i]); \ } - /* First the options that are only allowed for root */ + /* First the options that are not allowed with elevated privileges */ if (!strcmp(argv[i], "-modulepath") || !strcmp(argv[i], "-logfile")) { - if ( (geteuid() == 0) && (getuid() != 0) ) { - FatalError("The '%s' option can only be used by root.\n", argv[i]); + if (xf86PrivsElevated()) { + FatalError("The '%s' option cannot be used with " + "elevated privileges.\n", argv[i]); } else if (!strcmp(argv[i], "-modulepath")) { @@ -1098,9 +1148,9 @@ ddxProcessArgument(int argc, char **argv, int i) if (!strcmp(argv[i], "-config") || !strcmp(argv[i], "-xf86config")) { CHECK_FOR_REQUIRED_ARGUMENT(); - if (getuid() != 0 && !xf86PathIsSafe(argv[i + 1])) { + if (xf86PrivsElevated() && !xf86PathIsSafe(argv[i + 1])) { FatalError("\nInvalid argument for %s\n" - "\tFor non-root users, the file specified with %s must be\n" + "\tWith elevated privileges, the file specified with %s must be\n" "\ta relative path and must not contain any \"..\" elements.\n" "\tUsing default "__XCONFIGFILE__" search path.\n\n", argv[i], argv[i]); @@ -1111,9 +1161,9 @@ ddxProcessArgument(int argc, char **argv, int i) if (!strcmp(argv[i], "-configdir")) { CHECK_FOR_REQUIRED_ARGUMENT(); - if (getuid() != 0 && !xf86PathIsSafe(argv[i + 1])) { + if (xf86PrivsElevated() && !xf86PathIsSafe(argv[i + 1])) { FatalError("\nInvalid argument for %s\n" - "\tFor non-root users, the file specified with %s must be\n" + "\tWith elevated privileges, the file specified with %s must be\n" "\ta relative path and must not contain any \"..\" elements.\n" "\tUsing default "__XCONFIGDIR__" search path.\n\n", argv[i], argv[i]); @@ -1397,7 +1447,7 @@ ddxUseMsg(void) ErrorF("\n"); ErrorF("\n"); ErrorF("Device Dependent Usage\n"); - if (getuid() == 0 || geteuid() != 0) + if (!xf86PrivsElevated()) { ErrorF("-modulepath paths specify the module search path\n"); ErrorF("-logfile file specify a log file name\n"); diff --git a/hw/xfree86/common/xf86Priv.h b/hw/xfree86/common/xf86Priv.h index 1fe3d7e..49cae87 100644 --- a/hw/xfree86/common/xf86Priv.h +++ b/hw/xfree86/common/xf86Priv.h @@ -147,6 +147,7 @@ extern _X_EXPORT Bool xf86LoadModules(char **list, pointer *optlist); extern _X_EXPORT int xf86SetVerbosity(int verb); extern _X_EXPORT int xf86SetLogVerbosity(int verb); extern _X_EXPORT Bool xf86CallDriverProbe( struct _DriverRec * drv, Bool detect_only ); +extern _X_EXPORT Bool xf86PrivsElevated(void); #endif /* _NO_XF86_PROTOTYPES */ diff --git a/include/xorg-config.h.in b/include/xorg-config.h.in index 0d1ea91..ae0c8ec 100644 --- a/include/xorg-config.h.in +++ b/include/xorg-config.h.in @@ -139,4 +139,10 @@ /* Build with libdrm support */ #undef WITH_LIBDRM +/* Have setugid */ +#undef HAVE_ISSETUGID + +/* Have getresuid */ +#undef HAVE_GETRESUID + #endif /* _XORG_CONFIG_H_ */ -- 1.7.6.4