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

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fallback method
This commit is contained in:
Robert Griebl 2002-06-06 17:30:16 +00:00
parent fe1ef2bc62
commit 0c789a4255
1 changed files with 72 additions and 56 deletions
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128
applets/applets.c
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@ -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;
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
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_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
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!" );
}
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