From: Jesse Hathaway <jesse@mbuki-mvuki.org>
To: musl@lists.openwall.com, Jesse Hathaway <jesse@mbuki-mvuki.org>
Subject: [musl] Re: Pending patches for MT-fork stuff
Date: Tue, 29 Sep 2020 13:04:06 -0500 [thread overview]
Message-ID: <CANSNSoWQBT3Xf1rDdQGsKLAy6wQ1i-HmMmv=oALKOD2sRkgpjQ@mail.gmail.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 516 bytes --]
I was experiencing a hang when calling setreuid from a thread on musl
1.2.1 as well as on master with these patches applied. I have attached
a Go program which hangs when run as the root user outputting only:
main.go:31: Calling setreuid
Whereas with glibc the setreuid call completes successfully, with the
following output:
test.go:31: Calling setreuid
test.go:40: Running command
test.go:45: root
test.go:46: Command complete
I am happy to help troubleshoot the issue, yours kindly, Jesse
[-- Attachment #2: test.go --]
[-- Type: text/x-go, Size: 1574 bytes --]
package main
// #include <unistd.h>
// #include <errno.h>
import "C"
import (
"log"
"os"
"os/exec"
"os/signal"
"os/user"
"strconv"
"syscall"
"golang.org/x/sys/unix"
)
func runAsRoot() {
cmd := exec.Command("whoami")
uid := 0
unprivUser := "nobody"
lu, err := user.Lookup(unprivUser)
if err != nil {
log.Fatalf("Error: Unable to lookup user '%s': %v", unprivUser, err)
}
unprivUid, err := strconv.Atoi(lu.Uid)
if err != nil {
log.Fatalf("Error: %v", err)
}
log.Printf("Calling setreuid")
ret, errno := C.setreuid(C.uid_t(unprivUid), C.uid_t(uid))
if ret != 0 {
log.Fatalf("Error: returned %d, errno: %v", ret, errno)
}
euid := unix.Geteuid()
if euid != uid {
log.Fatalf("Error: euid %d, should be %d", euid, uid)
}
log.Printf("Running command")
stdoutStderr, err := cmd.CombinedOutput()
if err != nil {
log.Fatal(err)
}
log.Printf("%s", stdoutStderr)
log.Printf("Command complete")
return
}
func main() {
log.SetFlags(log.Lshortfile)
unprivUser := "nobody"
lu, err := user.Lookup(unprivUser)
if err != nil {
log.Fatalf("Error: Unable to lookup user '%s': %v", unprivUser, err)
}
uid, err := strconv.Atoi(lu.Uid)
if err != nil {
log.Fatalf("Error: %v", err)
}
ret, errno := C.setreuid(C.uid_t(0), C.uid_t(uid))
if ret != 0 {
log.Fatalf("Error: returned %d, errno: %v", ret, errno)
}
euid := unix.Geteuid()
if euid != uid {
log.Fatalf("Error: euid %d, should be %d", euid, uid)
}
go func() {
runAsRoot()
}()
sigs := make(chan os.Signal, 1)
signal.Notify(sigs, os.Interrupt, syscall.SIGTERM)
<-sigs
}
next reply other threads:[~2020-09-29 18:04 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-29 18:04 Jesse Hathaway [this message]
2020-09-29 18:36 ` Rich Felker
2020-09-29 18:51 ` Jesse Hathaway
2020-09-29 20:34 ` Rich Felker
2020-09-30 0:10 ` Rich Felker
2020-09-30 14:46 ` Jesse Hathaway
2020-09-30 15:55 ` Rich Felker
2021-03-03 14:40 ` Jesse Hathaway
2021-03-03 14:43 ` Rich Felker
2021-03-03 20:14 ` Jesse Hathaway
-- strict thread matches above, loose matches on Subject: below --
2020-09-29 17:19 Jesse Hathaway
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