fortify/internal/sandbox/overflow.go
Ophestra 6af8b8859f
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sandbox: read overflow ids
Signed-off-by: Ophestra <cat@gensokyo.uk>
2025-03-13 00:41:37 +09:00

38 lines
868 B
Go

package sandbox
import (
"bytes"
"log"
"os"
"strconv"
"sync"
)
var (
ofUid int
ofGid int
ofOnce sync.Once
)
const (
ofUidPath = "/proc/sys/kernel/overflowuid"
ofGidPath = "/proc/sys/kernel/overflowgid"
)
func mustReadOverflow() {
if v, err := os.ReadFile(ofUidPath); err != nil {
log.Fatalf("cannot read %q: %v", ofUidPath, err)
} else if ofUid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
log.Fatalf("cannot interpret %q: %v", ofUidPath, err)
}
if v, err := os.ReadFile(ofGidPath); err != nil {
log.Fatalf("cannot read %q: %v", ofGidPath, err)
} else if ofGid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
log.Fatalf("cannot interpret %q: %v", ofGidPath, err)
}
}
func OverflowUid() int { ofOnce.Do(mustReadOverflow); return ofUid }
func OverflowGid() int { ofOnce.Do(mustReadOverflow); return ofGid }