{"record":{"id":"37abb679957cc362","repo":"moonD4rk/HackBrowserData","slug":"sysctl-kern-proc-all-returned-invalid-data-length","errorCode":null,"errorMessage":"sysctl kern.proc.all returned invalid data length","messagePattern":"sysctl kern\\.proc\\.all returned invalid data length","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"masterkey/gcoredump_darwin.go","lineNumber":42,"sourceCode":"\t\"github.com/moond4rk/keychainbreaker\"\n)\n\nvar (\n\thomeDir, _        = os.UserHomeDir()\n\tloginKeychainPath = homeDir + \"/Library/Keychains/login.keychain-db\"\n)\n\n// findProcessByName returns the PID of the first process matching name.\n// If forceRoot is true, only matches processes owned by root (uid 0).\nfunc findProcessByName(name string, forceRoot bool) (int, error) {\n\tbuf, err := unix.SysctlRaw(\"kern.proc.all\")\n\tif err != nil {\n\t\treturn 0, fmt.Errorf(\"sysctl kern.proc.all failed: %w\", err)\n\t}\n\n\tkinfoSize := int(unsafe.Sizeof(unix.KinfoProc{}))\n\tif len(buf)%kinfoSize != 0 {\n\t\treturn 0, fmt.Errorf(\"sysctl kern.proc.all returned invalid data length\")\n\t}\n\n\tcount := len(buf) / kinfoSize\n\tfor i := 0; i < count; i++ {\n\t\tproc := (*unix.KinfoProc)(unsafe.Pointer(&buf[i*kinfoSize]))\n\t\tpname := byteSliceToString(proc.Proc.P_comm[:])\n\t\tif pname == name {\n\t\t\tif !forceRoot || proc.Eproc.Pcred.P_ruid == 0 {\n\t\t\t\treturn int(proc.Proc.P_pid), nil\n\t\t\t}\n\t\t}\n\t}\n\treturn 0, fmt.Errorf(\"securityd process not found\")\n}\n\ntype addressRange struct {\n\tstart uint64\n\tend   uint64","sourceCodeStart":24,"sourceCodeEnd":60,"githubUrl":"https://github.com/moonD4rk/HackBrowserData/blob/0503d04d7a8d0379d060268a74f1b149e5a0aad5/masterkey/gcoredump_darwin.go#L24-L60","documentation":"After the kern.proc.all sysctl succeeds, findProcessByName validates that the returned buffer is a whole number of KinfoProc structs. This error means the buffer length is not a multiple of sizeof(KinfoProc), so the kernel returned data in an unexpected layout and parsing it would read out of bounds or produce garbage process entries.","triggerScenarios":"Calling DecryptKeychainRecords on a macOS build whose kinfo_proc layout differs from the KinfoProc size the compiled binary expects — e.g. a binary built against an older x/sys/unix running on a newer macOS, or truncated sysctl output.","commonSituations":"Architecture/OS version mismatch (binary built for a different macOS release); stale golang.org/x/sys dependency with an outdated KinfoProc definition; exotic environments where sysctl returns partial data.","solutions":["Update golang.org/x/sys/unix and rebuild for the exact target macOS version/architecture.","Log len(buf) and the expected struct size to confirm how far off the layout is.","Use a different process enumeration API (libproc, pgrep) if the kinfo_proc layout cannot be matched.","Guard with the existing length check and fail fast — do not remove the validation to 'make it work', as parsing misaligned structs is unsafe."],"exampleFix":"// before\nkinfoSize := int(unsafe.Sizeof(unix.KinfoProc{}))\nif len(buf)%kinfoSize != 0 {\n\treturn 0, fmt.Errorf(\"sysctl kern.proc.all returned invalid data length\")\n}\n// after - include sizes in the error for diagnosis\nkinfoSize := int(unsafe.Sizeof(unix.KinfoProc{}))\nif len(buf)%kinfoSize != 0 {\n\treturn 0, fmt.Errorf(\"sysctl kern.proc.all returned invalid data length: %d bytes, not a multiple of kinfo_proc size %d (rebuild for this OS version?)\", len(buf), kinfoSize)\n}","handlingStrategy":"type-guard","validationCode":"kinfoSize := int(unsafe.Sizeof(unix.KinfoProc{}))\nif buf == nil || len(buf) == 0 || len(buf)%kinfoSize != 0 {\n\treturn fmt.Errorf(\"unexpected kern.proc.all buffer: %d bytes (kinfo_proc=%d)\", len(buf), kinfoSize)\n}","typeGuard":null,"tryCatchPattern":"pid, err := findProcessByName(name, forceRoot)\nif err != nil {\n\tif strings.Contains(err.Error(), \"invalid data length\") {\n\t\tlog.Warnf(\"kernel layout mismatch; rebuild for this macOS version: %v\", err)\n\t}\n\treturn err\n}","preventionTips":["Keep golang.org/x/sys updated and rebuild per target macOS version/arch.","Never disable the multiple-of-struct-size check; parsing misaligned data is unsafe.","Smoke-test process enumeration on each supported macOS release."],"tags":["macos","sysctl","process-enumeration","memory-layout"],"backgroundTag":"unexpected-response-shape","analyzedSha":"0503d04d7a8d0379d060268a74f1b149e5a0aad5","analyzedAt":"2026-09-06T13:38:28.707Z","contentChangedAt":"2026-09-06T13:38:28.707Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}