Tito writes,

"This patch fixes all the bugs in id previously spotted by vodz and me.
The binary size increased a bit,  but now it should work as expected."

1 files changed, 35 insertions, 41 deletions

diff --git a/coreutils/id.c b/coreutils/id.c
index 76331e48f..d5182b953 100644
--- a/coreutils/id.c
+++ b/coreutils/id.c
@@ -26,12 +26,9 @@
  */
 
 #include "busybox.h"
-#include "grp_.h"
 #include "pwd_.h"
 #include <stdio.h>
 #include <unistd.h>
-#include <getopt.h>
-#include <string.h>
 #include <sys/types.h>
 
 #ifdef CONFIG_SELINUX
@@ -44,21 +41,26 @@
 #define JUST_USER         4
 #define JUST_GROUP        8
 
-void printf_full(unsigned int id, char *arg, char prefix)
+static short printf_full(unsigned int id, const char *arg, const char prefix)
 {       
-        printf("%cid=%u",prefix, id);
-        if(arg)
-                printf("(%s) ", arg);
+        const char *fmt = "%cid=%u";
+        short status=EXIT_FAILURE;
+        
+        if(arg) {
+                fmt = "%cid=%u(%s)";
+                status=EXIT_SUCCESS;
+        }
+        bb_printf(fmt, prefix, id, arg);
+        return status;
 }
 
 extern int id_main(int argc, char **argv)
 {
         struct passwd *p;
-        char *user;
-        char *group;
         uid_t uid;
         gid_t gid;
-        int flags;
+        unsigned long flags;
+        short status;
 #ifdef CONFIG_SELINUX
         int is_flask_enabled_flag = is_flask_enabled();
 #endif
@@ -67,8 +69,9 @@ extern int id_main(int argc, char **argv)
         flags = bb_getopt_ulflags(argc, argv, "rnug");
 
         if ((flags & 0x80000000UL)
-         /* Don't allow -n -r -nr */
+        /* Don't allow -n -r -nr */
         || (flags <= 3 && flags > 0) 
+        /* Don't allow more than one username */
         || (argc > optind + 1))
                 bb_show_usage();
         
@@ -80,54 +83,45 @@ extern int id_main(int argc, char **argv)
                 gid = getgid();
         }
         
-        if(argv[optind])
-        {
-
+        if(argv[optind]) {
                 p=getpwnam(argv[optind]);
-                /* this is needed because it exits on failure */
+                /* my_getpwnam is needed because it exits on failure */
                 uid = my_getpwnam(argv[optind]);
                 gid = p->pw_gid;
                 /* in this case PRINT_REAL is the same */ 
         }
-        
-        user=my_getpwuid(NULL, uid, (flags & JUST_USER) ? -1 : 0);
 
-        if(flags & JUST_USER)
-        {
-                gid=uid;
-                group=user;
-                goto PRINT; 
-        }
-        
-        group=my_getgrgid(NULL, gid, (flags & JUST_GROUP) ? -1 : 0);
-
-        if(flags & JUST_GROUP) 
-        {
-PRINT:          
-                if(flags & NAME_NOT_NUMBER)
-                        puts(group);
-                else
-                        printf ("%u\n", gid);
+        if(flags & (JUST_GROUP | JUST_USER)) {
+                /* JUST_GROUP and JUST_USER are mutually exclusive */
+                if(flags & NAME_NOT_NUMBER) {
+                        /* my_getpwuid and my_getgrgid exit on failure so puts cannot segfault */
+                        puts((flags & JUST_USER) ? my_getpwuid(NULL, uid, -1 ) : my_getgrgid(NULL, gid, -1 ));
+                } else {
+                        bb_printf("%u\n",(flags & JUST_USER) ? uid : gid);
+                }
+                /* exit */ 
                 bb_fflush_stdout_and_exit(EXIT_SUCCESS);
         }
-        
+
         /* Print full info like GNU id */
-        printf_full(uid, user, 'u');
-        printf_full(gid, group, 'g');
+        /* my_getpwuid doesn't exit on failure here */
+        status=printf_full(uid, my_getpwuid(NULL, uid, 0), 'u');
+        putchar(' ');
+        /* my_getgrgid doesn't exit on failure here */
+        status|=printf_full(gid, my_getgrgid(NULL, gid, 0), 'g');
 #ifdef CONFIG_SELINUX
-        if(is_flask_enabled_flag)
-        {
+        if(is_flask_enabled_flag) {
                 security_id_t mysid = getsecsid();
                 char context[80];
                 int len = sizeof(context);
                 context[0] = '\0';
                 if(security_sid_to_context(mysid, context, &len))
                         strcpy(context, "unknown");
-                printf("context=%s", context);
+                bb_printf(" context=%s", context);
         }
 #endif
-        puts("");
-        bb_fflush_stdout_and_exit((user && group) ? EXIT_SUCCESS : EXIT_FAILURE);
+        putchar('\n');
+        bb_fflush_stdout_and_exit(status);
 }
 
 /* END CODE */