Root priviledges can be restored after setuid(1000) in musl libc
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musl libc allows you to change uid to root even after supposedly dropping permissions with setuid(1000). I am not able to reproduce the problem with glibc.
Code:
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
int main(void)
uid_t r, e, s;
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(1000) != 0)
puts("setuid(1000) failed");
else
puts("setuid(1000) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(0) != 0)
puts("setuid(0) failed");
else
puts("setuid(0) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
return 0;
which after compiling with gcc -o setuidtest setuidtest.c produces the following output when running as root
0 0 0
setuid(1000) succeded
1000 1000 1000
setuid(0) succeded
0 0 0
I am running Void Linux with kernel version 4.18_1 and musl version 1.1.20_2
linux security setuid
asked 17 mins ago
apilat
61
add a comment |Â
up vote
0
down vote
favorite
musl libc allows you to change uid to root even after supposedly dropping permissions with setuid(1000). I am not able to reproduce the problem with glibc.
Code:
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
int main(void)
uid_t r, e, s;
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(1000) != 0)
puts("setuid(1000) failed");
else
puts("setuid(1000) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(0) != 0)
puts("setuid(0) failed");
else
puts("setuid(0) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
return 0;
which after compiling with gcc -o setuidtest setuidtest.c produces the following output when running as root
0 0 0
setuid(1000) succeded
1000 1000 1000
setuid(0) succeded
0 0 0
I am running Void Linux with kernel version 4.18_1 and musl version 1.1.20_2
linux security setuid
asked 17 mins ago
apilat
61
add a comment |Â
up vote
0
down vote
favorite
up vote
0
down vote
favorite
musl libc allows you to change uid to root even after supposedly dropping permissions with setuid(1000). I am not able to reproduce the problem with glibc.
Code:
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
int main(void)
uid_t r, e, s;
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(1000) != 0)
puts("setuid(1000) failed");
else
puts("setuid(1000) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(0) != 0)
puts("setuid(0) failed");
else
puts("setuid(0) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
return 0;
which after compiling with gcc -o setuidtest setuidtest.c produces the following output when running as root
0 0 0
setuid(1000) succeded
1000 1000 1000
setuid(0) succeded
0 0 0
I am running Void Linux with kernel version 4.18_1 and musl version 1.1.20_2
linux security setuid
asked 17 mins ago
apilat
61
musl libc allows you to change uid to root even after supposedly dropping permissions with setuid(1000). I am not able to reproduce the problem with glibc.
Code:
#define _GNU_SOURCE
#include <unistd.h>
#include <stdio.h>
int main(void)
uid_t r, e, s;
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(1000) != 0)
puts("setuid(1000) failed");
else
puts("setuid(1000) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
if (setuid(0) != 0)
puts("setuid(0) failed");
else
puts("setuid(0) succeded");
getresuid(&r, &e, &s);
printf("%d %d %dn", r, e, s);
return 0;
which after compiling with gcc -o setuidtest setuidtest.c produces the following output when running as root
0 0 0
setuid(1000) succeded
1000 1000 1000
setuid(0) succeded
0 0 0
I am running Void Linux with kernel version 4.18_1 and musl version 1.1.20_2
linux security setuid
linux security setuid
asked 17 mins ago
apilat
61
asked 17 mins ago
apilat
61
asked 17 mins ago
apilat
61
asked 17 mins ago
apilat
61
asked 17 mins ago
apilat
61
61
add a comment |Â
add a comment |Â
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