0c789a425 — BusyBox

Subject

If config file can not be parsed, use compiled in BB_SUID_... values as a fallback method

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

applets/applets.c +71 -55

applets/applets.c+71 -55

@@ -53,8 +53,9 @@ static void check_suid ( struct BB_applet *app );
	#include "pwd.h"
	#include "grp.h"

-	static void parse_error ( int line, const char *err );
-	static void parse_config_file ( void );
+	static int parse_config_file ( void );
+
+	static int config_ok;

	#define CONFIG_FILE "/etc/busybox.conf"

@@ -119,7 +120,7 @@ void run_applet_by_name(const char name, int argc, char *argv)

	#ifdef CONFIG_FEATURE_SUID_CONFIG
	if ( recurse_level == 0 )
-	parse_config_file ( );
+	config_ok = parse_config_file ( );
	#endif

	recurse_level++;
@@ -183,42 +184,53 @@ void check_suid ( struct BB_applet *applet )
	uid_t rgid = getgid ( );

	#ifdef CONFIG_FEATURE_SUID_CONFIG
-	struct BB_suid_config *sct;
-
-	for ( sct = suid_config; sct; sct = sct-> m_next ) {
-	if ( sct-> m_applet == applet )
-	break;
-	}
-	if ( sct ) {
-	mode_t m = sct-> m_mode;
+	if ( config_ok ) {
+	struct BB_suid_config *sct;

-	if ( sct-> m_uid == ruid ) // same uid
-	m >>= 6;
-	else if (( sct-> m_gid == rgid ) \|\| ingroup ( ruid, sct-> m_gid )) // same group / in group
-	m >>= 3;
+	for ( sct = suid_config; sct; sct = sct-> m_next ) {
+	if ( sct-> m_applet == applet )
+	break;
+	}
+	if ( sct ) {
+	mode_t m = sct-> m_mode;
+
+	if ( sct-> m_uid == ruid ) // same uid
+	m >>= 6;
+	else if (( sct-> m_gid == rgid ) \|\| ingroup ( ruid, sct-> m_gid )) // same group / in group
+	m >>= 3;

-	if (!( m & S_IXOTH )) // is x bit not set ?
-	error_msg_and_die ( "You have no permission to run this applet!" );
-
-	if (( sct-> m_mode & ( S_ISGID \| S_IXGRP )) == ( S_ISGID \| S_IXGRP )) { // both have to be set for sgid
-	if ( setegid ( sct-> m_gid ))
-	error_msg_and_die ( "BusyBox binary has insufficient rights to set proper GID for applet!" );
+	if (!( m & S_IXOTH )) // is x bit not set ?
+	error_msg_and_die ( "You have no permission to run this applet!" );
+
+	if (( sct-> m_mode & ( S_ISGID \| S_IXGRP )) == ( S_ISGID \| S_IXGRP )) { // both have to be set for sgid
+	if ( setegid ( sct-> m_gid ))
+	error_msg_and_die ( "BusyBox binary has insufficient rights to set proper GID for applet!" );
+	}
+	else
+	setgid ( rgid ); // no sgid -> drop
+
+	if ( sct-> m_mode & S_ISUID ) {
+	if ( seteuid ( sct-> m_uid ))
+	error_msg_and_die ( "BusyBox binary has insufficient rights to set proper UID for applet!" );
+	}
+	else
+	setuid ( ruid ); // no suid -> drop
	}
-	else
-	setgid ( rgid ); // no sgid -> drop
-
-	if ( sct-> m_mode & S_ISUID ) {
-	if ( seteuid ( sct-> m_uid ))
-	error_msg_and_die ( "BusyBox binary has insufficient rights to set proper UID for applet!" );
-	}
-	else
-	setuid ( ruid ); // no suid -> drop
+	else { // default: drop all priviledges
+	setgid ( rgid );
+	setuid ( ruid );
+	}
+	return;
	}
-	else { // default: drop all priviledges
-	setgid ( rgid );
-	setuid ( ruid );
+	else {
+	static int onetime = 0;
+
+	if ( !onetime ) {
+	onetime = 1;
+	fprintf ( stderr, "Using fallback suid method\n" );
+	}
	}
-	#else
+	#endif

	if ( applet-> need_suid == _BB_SUID_ALWAYS ) {
	if ( geteuid ( ) != 0 )
@@ -228,23 +240,20 @@ void check_suid ( struct BB_applet *applet )
	setgid ( rgid ); // drop all priviledges
	setuid ( ruid );
	}
-	#endif
	}

	#ifdef CONFIG_FEATURE_SUID_CONFIG

-	void parse_error ( int line, const char *err )
-	{
-	char msg [512];
-	snprintf ( msg, sizeof( msg ) - 1, "Parse error in %s, line %d: %s", CONFIG_FILE, line, err );

-	error_msg_and_die ( msg );
-	}
+	#define parse_error(x) { err=x; goto pe_label; }


-	void parse_config_file ( void )
+	int parse_config_file ( void )
	{
	struct stat st;
+	char *err = 0;
+	FILE *f = 0;
+	int lc = 0;

	suid_config = 0;

@@ -253,12 +262,11 @@ void parse_config_file ( void )
	// is it owned by root with no write perm. for group and others ?
	if ( S_ISREG( st. st_mode ) && ( st. st_uid == 0 ) && (!( st. st_mode & ( S_IWGRP \| S_IWOTH )))) {
	// that's ok .. then try to open it
-	FILE *f = fopen ( CONFIG_FILE, "r" );
+	f = fopen ( CONFIG_FILE, "r" );

	if ( f ) {
-	char buffer [4096];
+	char buffer [256];
	int section = 0;
-	int lc = 0;

	while ( fgets ( buffer, sizeof( buffer ) - 1, f )) {
	char c = buffer [0];
@@ -280,7 +288,7 @@ void parse_config_file ( void )
	p = strchr ( buffer, ']' );

	if ( !p \|\| ( p == ( buffer + 1 ))) // no matching ] or empty []
-	parse_error ( lc, "malformed section header" );
+	parse_error ( "malformed section header" );

	*p = 0;

@@ -298,7 +306,7 @@ void parse_config_file ( void )
	p = strchr ( buffer, '=' ); // <key>[::space::]=[::space::]<value>

	if ( !p \|\| ( p == ( buffer + 1 ))) // no = or key is empty
-	parse_error ( lc, "malformed keyword" );
+	parse_error ( "malformed keyword" );

	l = p - buffer;
	while ( isspace ( buffer [--l] )) { } // skip whitespace
@@ -321,7 +329,7 @@ void parse_config_file ( void )
	case 's': sct-> m_mode \|= S_ISUID; // no break
	case 'x': sct-> m_mode \|= S_IXUSR; break;
	case '-': break;
-	default : parse_error ( lc, "invalid user mode" );
+	default : parse_error ( "invalid user mode" );
	}

	switch ( *p++ ) {
@@ -329,7 +337,7 @@ void parse_config_file ( void )
	case 'x': sct-> m_mode \|= S_IXGRP; break;
	case 'S': break;
	case '-': break;
-	default : parse_error ( lc, "invalid group mode" );
+	default : parse_error ( "invalid group mode" );
	}

	switch ( *p ) {
@@ -337,7 +345,7 @@ void parse_config_file ( void )
	case 'x': sct-> m_mode \|= S_IXOTH; break;
	case 'T':
	case '-': break;
-	default : parse_error ( lc, "invalid other mode" );
+	default : parse_error ( "invalid other mode" );
	}

	while ( isspace ( *++p )) { } // skip whitespace
@@ -345,20 +353,20 @@ void parse_config_file ( void )
	if ( isdigit ( *p )) {
	sct-> m_uid = strtol ( p, &p, 10 );
	if ( *p++ != '.' )
-	parse_error ( lc, "parsing <uid>.<gid>" );
+	parse_error ( "parsing <uid>.<gid>" );
	}
	else {
	struct passwd *pwd;
	char *p2 = strchr ( p, '.' );

	if ( !p2 )
-	parse_error ( lc, "parsing <uid>.<gid>" );
+	parse_error ( "parsing <uid>.<gid>" );

	*p2 = 0;
	pwd = getpwnam ( p );

	if ( !pwd )
-	parse_error ( lc, "invalid user name" );
+	parse_error ( "invalid user name" );

	sct-> m_uid = pwd-> pw_uid;
	p = p2 + 1;
@@ -369,7 +377,7 @@ void parse_config_file ( void )
	struct group *grp = getgrnam ( p );

	if ( !grp )
-	parse_error ( lc, "invalid group name" );
+	parse_error ( "invalid group name" );

	sct-> m_gid = grp-> gr_gid;
	}
@@ -381,12 +389,20 @@ void parse_config_file ( void )
	}
	}
	else
-	parse_error ( lc, "keyword not within section" );
+	parse_error ( "keyword not within section" );
	}
	fclose ( f );
	}
	}
	}
+	return 1;
+
+	pe_label:
+	fprintf ( stderr, "Parse error in %s, line %d: %s\n", CONFIG_FILE, lc, err );
+
+	if ( f )
+	fclose ( f );
+	return 0;
	}

	#endif