diff options
| author | Ayush Ranjan <ayushranjan@google.com> | 2020-09-02 15:39:51 -0700 |
|---|---|---|
| committer | Andrei Vagin <avagin@gmail.com> | 2020-09-09 17:53:10 -0700 |
| commit | 3e87c8e14d1552ec918256639797b07aa999bd0a (patch) | |
| tree | 385ec528745700f43df35ff663c8f88e52f3ddaf | |
| parent | 9b7f3ce38ac818dcb9edde7eb7288de665d3de10 (diff) | |
[vfs] Fix error handling in overlayfs OpenAt.
Updates #1199
PiperOrigin-RevId: 329802274
| -rw-r--r-- | pkg/sentry/fsimpl/overlay/filesystem.go | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/pkg/sentry/fsimpl/overlay/filesystem.go b/pkg/sentry/fsimpl/overlay/filesystem.go index e720bfb0b..63df86481 100644 --- a/pkg/sentry/fsimpl/overlay/filesystem.go +++ b/pkg/sentry/fsimpl/overlay/filesystem.go @@ -743,6 +743,9 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf start := rp.Start().Impl().(*dentry) if rp.Done() { + if mayCreate && rp.MustBeDir() { + return nil, syserror.EISDIR + } if mustCreate { return nil, syserror.EEXIST } @@ -766,6 +769,10 @@ 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) @@ -774,12 +781,11 @@ afterTrailingSymlink: parent.dirMu.Unlock() return fd, err } + parent.dirMu.Unlock() if err != nil { - parent.dirMu.Unlock() return nil, err } // Open existing child or follow symlink. - parent.dirMu.Unlock() if mustCreate { return nil, syserror.EEXIST } @@ -794,6 +800,9 @@ afterTrailingSymlink: start = parent goto afterTrailingSymlink } + if rp.MustBeDir() && !child.isDir() { + return nil, syserror.ENOTDIR + } if mayWrite { if err := child.copyUpLocked(ctx); err != nil { return nil, err |