The branch stable/15 has been updated by rmacklem:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=c69e0be70f4693940873f16e5019bd229a410369

commit c69e0be70f4693940873f16e5019bd229a410369
Author:     Rick Macklem <[email protected]>
AuthorDate: 2025-10-27 14:24:47 +0000
Commit:     Rick Macklem <[email protected]>
CommitDate: 2025-10-30 00:57:59 +0000

    nfs_nfsdserv.c: Add a sanity check for layout commit cnt
    
    If a client were to send a LayoutCommit (seldom
    used and only for a pNFS server) with a bogus
    cnt, there could be problems with a malloc() call
    that uses it.
    
    This patch adds a sanity check for the cnt. Note
    that RFC8881 does not specify any upper bound
    on the cnt.
    
    (cherry picked from commit 1a679fb907962843f01b103ec672136a8f8d8edb)
---
 sys/fs/nfsserver/nfs_nfsdserv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/fs/nfsserver/nfs_nfsdserv.c b/sys/fs/nfsserver/nfs_nfsdserv.c
index a881968b03be..9dda65d5cbcf 100644
--- a/sys/fs/nfsserver/nfs_nfsdserv.c
+++ b/sys/fs/nfsserver/nfs_nfsdserv.c
@@ -5128,6 +5128,11 @@ nfsrvd_layoutcommit(struct nfsrv_descript *nd, __unused 
int isdgram,
                NFSM_DISSECT(tl, uint32_t *, 2 * NFSX_UNSIGNED);
        layouttype = fxdr_unsigned(int, *tl++);
        maxcnt = fxdr_unsigned(int, *tl);
+       /* There is no limit in the RFC, so use 1000 as a sanity limit. */
+       if (maxcnt < 0 || maxcnt > 1000) {
+               error = NFSERR_BADXDR;
+               goto nfsmout;
+       }
        if (maxcnt > 0) {
                layp = malloc(maxcnt + 1, M_TEMP, M_WAITOK);
                error = nfsrv_mtostr(nd, layp, maxcnt);

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