[src/trunk]: src/sys/nfs nfs: Use unsigned name lengths so we don't trip over...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/32c0297631e9
branches:  trunk
changeset: 374003:32c0297631e9
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu Mar 23 19:52:52 2023 +0000

description:
nfs: Use unsigned name lengths so we don't trip over negative ones.

- nfsm_strsiz is only used with uint32_t in callers, but let's not
  leave it as a rake to step on.

- nfsm_srvnamesiz is abused with signed s.  The internal conversion
  to unsigned serves to reject both negative and too-large values in
  such callers.

  XXX Should make all callers use unsigned, rather than flipping back
  and forth between signed and unsigned for name lengths.

XXX pullup-8
XXX pullup-9
XXX pullup-10

diffstat:

 sys/nfs/nfsm_subs.h |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (28 lines):

diff -r 1c3974da7422 -r 32c0297631e9 sys/nfs/nfsm_subs.h
--- a/sys/nfs/nfsm_subs.h       Thu Mar 23 19:52:42 2023 +0000
+++ b/sys/nfs/nfsm_subs.h       Thu Mar 23 19:52:52 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfsm_subs.h,v 1.56 2023/03/23 19:52:33 riastradh Exp $ */
+/*     $NetBSD: nfsm_subs.h,v 1.57 2023/03/23 19:52:52 riastradh Exp $ */
 
 /*
  * Copyright (c) 1989, 1993
@@ -366,7 +366,7 @@
 
 #define        nfsm_strsiz(s,m) \
                { nfsm_dissect(tl,uint32_t *,NFSX_UNSIGNED); \
-               if (((s) = fxdr_unsigned(uint32_t,*tl)) > (m)) { \
+               if ((uint32_t)((s) = fxdr_unsigned(uint32_t,*tl)) > (m)) { \
                        m_freem(mrep); \
                        error = EBADRPC; \
                        goto nfsmout; \
@@ -374,7 +374,8 @@
 
 #define        nfsm_srvnamesiz(s) \
                { nfsm_dissect(tl,uint32_t *,NFSX_UNSIGNED); \
-               if (((s) = fxdr_unsigned(uint32_t,*tl)) > NFS_MAXNAMLEN) \
+               if ((uint32_t)((s) = fxdr_unsigned(uint32_t,*tl)) > \
+                   NFS_MAXNAMLEN) \
                        error = NFSERR_NAMETOL; \
                if (error) \
                        nfsm_reply(0); \