git: b05be03ceea0 - main - pdrfork(2): do require RFPROCDESC | RFPROC

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=b05be03ceea0a95f7783ddc890885f34bb4023d4

commit b05be03ceea0a95f7783ddc890885f34bb4023d4
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-02-14 16:38:23 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-02-16 17:57:52 +0000

    pdrfork(2): do require RFPROCDESC | RFPROC
    
    when RFSPAWN is not specified, as stated in the man page.
    rfork(2) cannot modify non-curproc, which is why RFPROC is required,
    the syscall cannot act on arbitrary process descriptor.
    If RFPROCDESC is not specified, the syscall does not make sense,
    use rfork(2).
    
    Reported and tested by: pho
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D55306
---
 lib/libsys/pdfork.2  | 8 +++++---
 sys/kern/kern_fork.c | 5 +++++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/libsys/pdfork.2 b/lib/libsys/pdfork.2
index ad7eecb00dae..9cbeb65bc4fc 100644
--- a/lib/libsys/pdfork.2
+++ b/lib/libsys/pdfork.2
@@ -114,11 +114,13 @@ for a description of the possible
 flags.
 The
 .Fn pdrfork
-system call requires that the
+system call requires that both the
 .Va RFPROC
-or
+and
+.Va RFPROCDESC
+flags, or
 .Va RFSPAWN
-flag is specified.
+flag are specified.
 .Pp
 .Fn pdgetpid
 queries the process ID (PID) in the process descriptor
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 6313bf3bb651..36647ae44f08 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -214,6 +214,11 @@ sys_pdrfork(struct thread *td, struct pdrfork_args *uap)
 		fr.fr_flags = RFFDG | RFPROC | RFPPWAIT | RFMEM | RFPROCDESC;
 		fr.fr_flags2 = FR2_DROPSIG_CAUGHT;
 	} else {
+		if ((uap->rfflags & (RFPROC | RFPROCDESC)) !=
+		    (RFPROC | RFPROCDESC)) {
+			return (EXTERROR(EINVAL,
+			    "RFPROC|RFPROCDESC required %#jx", uap->rfflags));
+		}
 		fr.fr_flags = uap->rfflags;
 	}