nfsd: -EINVAL on invalid anonuid/gid instead of silent failure
If we're going to refuse to accept these it would be polite of us to at
least say so....
This introduces a slight complication since we need to grandfather in
exportfs's ill-advised use of -1 uid and gid on its test_export.
If it turns out there are other users passing down -1 we may need to
do something else.
Best might be to drop the checks entirely, but I'm not sure if other
parts of the kernel might assume that a task can't run as uid or gid -1.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index af51cf9..8513c59 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -580,16 +580,25 @@
if (err)
goto out4;
/*
+ * No point caching this if it would immediately expire.
+ * Also, this protects exportfs's dummy export from the
+ * anon_uid/anon_gid checks:
+ */
+ if (exp.h.expiry_time < seconds_since_boot())
+ goto out4;
+ /*
* For some reason exportfs has been passing down an
* invalid (-1) uid & gid on the "dummy" export which it
* uses to test export support. To make sure exportfs
* sees errors from check_export we therefore need to
* delay these checks till after check_export:
*/
+ err = -EINVAL;
if (!uid_valid(exp.ex_anon_uid))
goto out4;
if (!gid_valid(exp.ex_anon_gid))
goto out4;
+ err = 0;
}
expp = svc_export_lookup(&exp);