nfsd41: sanity check client drc maxreqs

Ensure the client requested maximum requests are between 1 and
NFSD_MAX_SLOTS_PER_SESSION

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d5caf2a709d2..99570c49add5 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -425,6 +425,11 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
 {
         int status = 0, np = fchan->maxreqs * NFSD_PAGES_PER_SLOT;
 
+        if (fchan->maxreqs < 1)
+                return nfserr_inval;
+        else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
+                fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;
+
         spin_lock(&nfsd_serv->sv_lock);
         if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages)
                 np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used;