git: 03e9e83f3586 - main - nfs_nfsdserv.c: Clip number of callback slots

The branch main has been updated by rmacklem:

URL: https://cgit.FreeBSD.org/src/commit/?id=03e9e83f358678bab5e4c1ddf9c9d8faa7183cbb

commit 03e9e83f358678bab5e4c1ddf9c9d8faa7183cbb
Author:     Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2026-05-05 00:04:00 +0000
Commit:     Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2026-05-05 00:04:00 +0000

    nfs_nfsdserv.c: Clip number of callback slots
    
    The client tells the server how many callback slots
    it can handle in the callback session.  However, the
    NFSv4.1/4.2 server can only handle a maximum of
    NFSV4_SLOTS slots.  This patch clips the client's
    value to that, to avoid using too high a slot#
    for a callback.
    
    Fortunately, I do not know of an extant client that
    specifies a value greater than NFSV4_SLOTS, so this
    patch is not really needed, as yet.  Also, the client
    rarely uses a slot# above 0 when doing callbacks.
    
    MFC after:      2 weeks
---
 sys/fs/nfsserver/nfs_nfsdserv.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/fs/nfsserver/nfs_nfsdserv.c b/sys/fs/nfsserver/nfs_nfsdserv.c
index 855d018e72d2..ad0f495bbd69 100644
--- a/sys/fs/nfsserver/nfs_nfsdserv.c
+++ b/sys/fs/nfsserver/nfs_nfsdserv.c
@@ -4869,6 +4869,14 @@ nfsrvd_createsession(struct nfsrv_descript *nd, __unused int isdgram,
 		*tl++ = txdr_unsigned(sep->sess_cbsess.nfsess_foreslots);
 		*tl++ = txdr_unsigned(1);
 		*tl = txdr_unsigned(0);			/* No RDMA. */
+		/*
+		 * Although the client accepts slot#s up to
+		 * sess_cbsess.nfsess_foreslots, the server can only use
+		 * a maximum of NFSV4_SLOTS, so clip it to avoid ever using
+		 * too high a slot.
+		 */
+		if (sep->sess_cbsess.nfsess_foreslots > NFSV4_SLOTS)
+			sep->sess_cbsess.nfsess_foreslots = NFSV4_SLOTS;
 	}
 nfsmout:
 	if (nd->nd_repstat != 0 && sep != NULL)