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| author | Ayush Ranjan <ayushranjan@google.com> | 2020-08-13 19:31:17 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-08-13 19:33:56 -0700 |
| commit | d6520e1d0592f99161faedef3eba49439b140917 (patch) | |
| tree | 302e0b765424bbcb46315b045b40fd707c3645d0 /pkg/sentry/fsimpl/gofer | |
| parent | d3bb50ebf85c1241ec91745eaca9fbbb86eb4211 (diff) | |
[vfs2][gofer] Fix file creation flags sent to gofer.
Fixes php runtime test ext/standard/tests/file/readfile_basic.phpt
Fixes #3516
fsgofers only want the access mode in the OpenFlags passed to Create(). If more
flags are supplied (like O_APPEND in this case), read/write from that fd will
fail with EBADF. See runsc/fsgofer/fsgofer.go:WriteAt()
VFS2 was providing more than just access modes. So filtering the flags using
p9.OpenFlagsModeMask == linux.O_ACCMODE fixes the issue.
Gofer in VFS1 also only extracts the access mode flags while making the create
RPC. See pkg/sentry/fs/gofer/path.go:Create()
Even in VFS2, when we open a handle, we extract out only the access mode flags
+ O_TRUNC.
See third_party/gvisor/pkg/sentry/fsimpl/gofer/handle.go:openHandle()
Added a test for this.
PiperOrigin-RevId: 326574829
Diffstat (limited to 'pkg/sentry/fsimpl/gofer')
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/filesystem.go | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go index 40fec890a..610a7ed78 100644 --- a/pkg/sentry/fsimpl/gofer/filesystem.go +++ b/pkg/sentry/fsimpl/gofer/filesystem.go @@ -1082,10 +1082,8 @@ func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.Resolving } creds := rp.Credentials() name := rp.Component() - // Filter file creation flags and O_LARGEFILE out; the create RPC already - // has the semantics of O_CREAT|O_EXCL, while some servers will choke on - // O_LARGEFILE. - createFlags := p9.OpenFlags(opts.Flags &^ (vfs.FileCreationFlags | linux.O_LARGEFILE)) + // We only want the access mode for creating the file. + createFlags := p9.OpenFlags(opts.Flags) & p9.OpenFlagsModeMask fdobj, openFile, createQID, _, err := dirfile.create(ctx, name, createFlags, (p9.FileMode)(opts.Mode), (p9.UID)(creds.EffectiveKUID), (p9.GID)(creds.EffectiveKGID)) if err != nil { dirfile.close(ctx) |