From 42b610d56750b4bb8e3d69b680e4fb538f8fb554 Mon Sep 17 00:00:00 2001
From: Ayush Ranjan <ayushranjan@google.com>
Date: Wed, 12 Aug 2020 17:17:17 -0700
Subject: [vfs2][gofer] Return appropriate errors when opening and creating
files.
Fixes php test ext/standard/tests/file/touch_variation5.phpt on vfs2.
Updates #3516
Also spotted a bug with O_EXCL, where we did not return EEXIST when we tried
to open the root of the filesystem with O_EXCL | O_CREAT.
Added some more tests for open() corner cases.
PiperOrigin-RevId: 326346863
---
pkg/sentry/fsimpl/gofer/filesystem.go | 11 +++++++++++
1 file changed, 11 insertions(+)
(limited to 'pkg/sentry/fsimpl/gofer')
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index eaef2594d..40fec890a 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -844,6 +844,13 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
}
}
if rp.Done() {
+ // Reject attempts to open mount root directory with O_CREAT.
+ if mayCreate && rp.MustBeDir() {
+ return nil, syserror.EISDIR
+ }
+ if mustCreate {
+ return nil, syserror.EEXIST
+ }
return start.openLocked(ctx, rp, &opts)
}
@@ -856,6 +863,10 @@ afterTrailingSymlink:
if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
+ // Reject attempts to open directories with O_CREAT.
+ if mayCreate && rp.MustBeDir() {
+ return nil, syserror.EISDIR
+ }
// Determine whether or not we need to create a file.
parent.dirMu.Lock()
child, err := fs.stepLocked(ctx, rp, parent, false /* mayFollowSymlinks */, &ds)
--
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