git: 014ce35640bf - stable/14 - vfs: Return early from sysctl_vfs_ctl() if no input was given

The branch stable/14 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=014ce35640bf1a00edf3f7163c3248bb484c29f2

commit 014ce35640bf1a00edf3f7163c3248bb484c29f2
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2025-03-20 01:34:18 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2025-04-06 13:54:03 +0000

    vfs: Return early from sysctl_vfs_ctl() if no input was given
    
    Otherwise we end up searching for a mountpoint using an uninitialized
    key, and likely failing the version test.  This violates KMSAN's
    invariants, so simply return immediately instead.
    
    MFC after:      2 weeks
    
    (cherry picked from commit d8703cd80247ca203b817305753bda2b7dbfb5ef)
---
 sys/kern/vfs_subr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 5a0a7f9161ed..6c116448a59a 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -6451,6 +6451,8 @@ sysctl_vfs_ctl(SYSCTL_HANDLER_ARGS)
 	int error;
 	struct mount *mp;
 
+	if (req->newptr == NULL)
+		return (EINVAL);
 	error = SYSCTL_IN(req, &vc, sizeof(vc));
 	if (error)
 		return (error);