archive/tarheader: fix FreeBSD hdr for regular files

This update addresses an issue where the stat call on FreeBSD could
return -1 for regular files. This led to incorrect Devmajor and
Devminor values, which should be zero in such cases. Refer to the
discussion on this bug in the following PR:
https://github.com/containerd/containerd/pull/5991.

The code change now handles this scenario appropriately.

Signed-off-by: Artem Khramov <akhramov@pm.me>
This commit is contained in:
Artem Khramov 2023-08-09 05:46:49 +03:00
parent 165f8e414e
commit 1fd3a46526
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@ -28,6 +28,7 @@ package tarheader
import ( import (
"archive/tar" "archive/tar"
"os" "os"
"runtime"
"syscall" "syscall"
"golang.org/x/sys/unix" "golang.org/x/sys/unix"
@ -39,7 +40,7 @@ func init() {
// statUnix populates hdr from system-dependent fields of fi without performing // statUnix populates hdr from system-dependent fields of fi without performing
// any OS lookups. // any OS lookups.
// From https://github.com/moby/moby/blob/v23.0.1/pkg/archive/archive_unix.go#L52-L70 // From https://github.com/moby/moby/blob/2cccb1f02c83aaacef3c15fa43f3b64d57f315f8/pkg/archive/archive_unix.go#L46-L76
func statUnix(fi os.FileInfo, hdr *tar.Header) error { func statUnix(fi os.FileInfo, hdr *tar.Header) error {
s, ok := fi.Sys().(*syscall.Stat_t) s, ok := fi.Sys().(*syscall.Stat_t)
if !ok { if !ok {
@ -49,6 +50,21 @@ func statUnix(fi os.FileInfo, hdr *tar.Header) error {
hdr.Uid = int(s.Uid) hdr.Uid = int(s.Uid)
hdr.Gid = int(s.Gid) hdr.Gid = int(s.Gid)
// Devmajor and Devminor are only needed for special devices.
// In FreeBSD, RDev for regular files is -1 (unless overridden by FS):
// https://cgit.freebsd.org/src/tree/sys/kern/vfs_default.c?h=stable/13#n1531
// (NODEV is -1: https://cgit.freebsd.org/src/tree/sys/sys/param.h?h=stable/13#n241).
// ZFS in particular does not override the default:
// https://cgit.freebsd.org/src/tree/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c?h=stable/13#n2027
// Since `Stat_t.Rdev` is uint64, the cast turns -1 into (2^64 - 1).
// Such large values cannot be encoded in a tar header.
if runtime.GOOS == "freebsd" && hdr.Typeflag != tar.TypeBlock && hdr.Typeflag != tar.TypeChar {
return nil
}
if s.Mode&unix.S_IFBLK != 0 || if s.Mode&unix.S_IFBLK != 0 ||
s.Mode&unix.S_IFCHR != 0 { s.Mode&unix.S_IFCHR != 0 {
hdr.Devmajor = int64(unix.Major(uint64(s.Rdev))) hdr.Devmajor = int64(unix.Major(uint64(s.Rdev)))