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correct-mkdir: infer cache owner from parent dir
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When running as sudo (without the -H flag), the HOME environment
variable is /var/root by default.

The correct-mkdir module was reading env.HOME to determine the
appropriate uid and gid for files written to the cache folder.

However, this is rarely correct.  In practice, this module was reading
env.SUDO_UID and env.SUDO_GID in some cases, but matching ownership on
/var/root in others.

This patch changes correct-mkdir to match the behavior of cacache v12,
where ownership of a file or folder is inferred from the ownership of
its nearest parent directory.
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isaacs committed Jul 16, 2019
1 parent 25f4f73 commit 2c61ce6
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Showing 2 changed files with 48 additions and 106 deletions.
146 changes: 44 additions & 102 deletions lib/utils/correct-mkdir.js
Original file line number Diff line number Diff line change
@@ -1,123 +1,65 @@
var chownr = require('chownr')
var dezalgo = require('dezalgo')
var fs = require('graceful-fs')
var inflight = require('inflight')
var log = require('npmlog')
var mkdirp = require('mkdirp')
const chownr = require('chownr')
const fs = require('graceful-fs')
const inflight = require('inflight')
const log = require('npmlog')
const mkdirp = require('mkdirp')
const { dirname } = require('path')

// retain ownership of the parent dir
// this matches behavior in cacache to infer the cache ownership
// based on the ownership of the cache folder or it is parent.

// memoize the directories created by this step
var stats = {}
var effectiveOwner
module.exports = function correctMkdir (path, cb) {
cb = dezalgo(cb)
cb = inflight('correctMkdir:' + path, cb)
cb = inflight('correctMkdir: ' + path, cb)
if (!cb) {
return log.verbose('correctMkdir', path, 'correctMkdir already in flight; waiting')
} else {
log.verbose('correctMkdir', path, 'correctMkdir not in flight; initializing')
}

if (stats[path]) return cb(null, stats[path])

fs.stat(path, function (er, st) {
if (er) return makeDirectory(path, cb)
if (!process.getuid) {
log.verbose('makeCacheDir', 'UID & GID are irrelevant on', process.platform)
return mkdirp(path, (er, made) => cb(er, { uid: 0, gid: 0 }))
}

if (!st.isDirectory()) {
log.error('correctMkdir', 'invalid dir %s', path)
inferOwner(path, (er, owner) => {
if (er) {
log.error('correctMkdir', 'failed to infer path ownership %s', path)
return cb(er)
}

var ownerStats = calculateOwner()
// there's always a chance the permissions could have been frobbed, so fix
if (st.uid !== ownerStats.uid) {
stats[path] = ownerStats
setPermissions(path, ownerStats, cb)
} else {
stats[path] = st
cb(null, stats[path])
}
})
}

function calculateOwner () {
if (!effectiveOwner) {
effectiveOwner = { uid: 0, gid: 0 }

// Pretty much only on windows
if (!process.getuid) {
return effectiveOwner
}

effectiveOwner.uid = +process.getuid()
effectiveOwner.gid = +process.getgid()

if (effectiveOwner.uid === 0) {
if (process.env.SUDO_UID) effectiveOwner.uid = +process.env.SUDO_UID
if (process.env.SUDO_GID) effectiveOwner.gid = +process.env.SUDO_GID
}
}

return effectiveOwner
}

function makeDirectory (path, cb) {
cb = inflight('makeDirectory:' + path, cb)
if (!cb) {
return log.verbose('makeDirectory', path, 'creation already in flight; waiting')
} else {
log.verbose('makeDirectory', path, 'creation not in flight; initializing')
}

var owner = calculateOwner()

if (!process.getuid) {
return mkdirp(path, function (er) {
log.verbose('makeCacheDir', 'UID & GID are irrelevant on', process.platform)

stats[path] = owner
return cb(er, stats[path])
})
}

if (owner.uid !== 0 || !process.env.HOME) {
log.silly(
'makeDirectory', path,
'uid:', owner.uid,
'gid:', owner.gid
)
stats[path] = owner
mkdirp(path, afterMkdir)
} else {
fs.stat(process.env.HOME, function (er, st) {
mkdirp(path, (er, made) => {
if (er) {
log.error('makeDirectory', 'homeless?')
log.error('correctMkdir', 'failed to make directory %s', path)
return cb(er)
}

log.silly(
'makeDirectory', path,
'uid:', st.uid,
'gid:', st.gid
)
stats[path] = st
mkdirp(path, afterMkdir)
chownr(made || path, owner.uid, owner.gid, (er) => cb(er, owner))
})
}

function afterMkdir (er, made) {
if (er || !stats[path] || isNaN(stats[path].uid) || isNaN(stats[path].gid)) {
return cb(er, stats[path])
}

if (!made) return cb(er, stats[path])
})
}

setPermissions(made, stats[path], cb)
const pathToOwner = new Map()
const inferOwner = (path, cb) => {
if (pathToOwner.has(path)) {
return cb(null, pathToOwner.get(path))
}
}

function setPermissions (path, st, cb) {
chownr(path, st.uid, st.gid, function (er) {
if (er && er.code === 'ENOENT') return cb(null, st)
return cb(er, st)
const parent = dirname(path)
fs.lstat(path, (er, st) => {
if (er && parent !== path) {
inferOwner(parent, (er, owner) => {
if (er) {
return cb(er)
}
pathToOwner.set(path, owner)
return cb(null, owner)
})
} else if (er) {
cb(er)
} else {
const owner = { uid: st.uid, gid: st.gid }
pathToOwner.set(path, owner)
cb(null, owner)
}
})
}
8 changes: 4 additions & 4 deletions test/tap/correct-mkdir.js
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@ var cache_dir = common.pkg
test('correct-mkdir: no race conditions', function (t) {
var mock_fs = {}
var did_hook = false
mock_fs.stat = function (path, cb) {
mock_fs.lstat = function (path, cb) {
if (path === cache_dir) {
// Return a non-matching owner
cb(null, {
Expand Down Expand Up @@ -60,7 +60,7 @@ test('correct-mkdir: no race conditions', function (t) {

test('correct-mkdir: ignore ENOENTs from chownr', function (t) {
var mock_fs = {}
mock_fs.stat = function (path, cb) {
mock_fs.lstat = function (path, cb) {
if (path === cache_dir) {
cb(null, {
isDirectory: function () {
Expand Down Expand Up @@ -99,7 +99,7 @@ test('correct-mkdir: SUDO_UID and SUDO_GID non-Windows', function (t) {
process.getuid = function () { return 0 }
process.getgid = function () { return 0 }
var mock_fs = {}
mock_fs.stat = function (path, cb) {
mock_fs.lstat = function (path, cb) {
if (path === cache_dir) {
cb(null, {
uid: 0,
Expand Down Expand Up @@ -134,7 +134,7 @@ test('correct-mkdir: SUDO_UID and SUDO_GID Windows', function (t) {
delete process.getuid
delete process.getgid
var mock_fs = {}
mock_fs.stat = function (path, cb) {
mock_fs.lstat = function (path, cb) {
if (path === cache_dir) {
cb(null, {
uid: 0,
Expand Down

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