Bug 91567

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User-Agent: Mozilla/5.0 (X11; U; Linux i586; en-US; rv:1.2.1) Gecko/20030225

Description of problem:
The setegid call sets the saved gid even though it should not. SUS says only
effective gid should be set. I looked at glibc source and it is calling
__setresgid(-1, euid,-1);

Version-Release number of selected component (if applicable):
kernel-2.4.20-13.9

How reproducible:
Always

Steps to Reproduce:
1. Compile and run the following program:

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
 
int main(void)
{
    struct passwd nobody;
    gid_t cur_rgid, cur_egid, cur_sgid;
    gid_t orig_rgid, orig_egid, orig_sgid;
 
    if (geteuid() != 0) {
        puts("Must be super/root for this test!");
        return 1;
    }
                                                                                
    nobody = *getpwnam("nobody");
    getresgid(&orig_rgid, &orig_egid, &orig_sgid);
    printf("getresgid reports rgid %d, egid %d, sgid %d\n", orig_rgid,
           orig_egid, orig_sgid);
    setegid(nobody.pw_gid);
    getresgid(&cur_rgid, &cur_egid, &cur_sgid);
    printf("getresgid reports rgid %d, egid %d, sgid %d\n", cur_rgid,
           cur_egid, cur_sgid);
    if (orig_sgid != cur_sgid) {
        puts("setegid() changed the saved set-gid");
        return 1;
    }
 
    return 0;
}


Actual Results:  getresgid reports rgid 0, egid 0, sgid 0
getresgid reports rgid 0, egid 99, sgid 99
setegid() changed the saved set-gid


Expected Results:  getresgid reports rgid 0, egid 0, sgid 0
getresgid reports rgid 0, egid 99, sgid 0


Additional info: