git: deaa609d065d - stable/15 - jaildesc: remove desc from the sysctl parameter list

The branch stable/15 has been updated by jamie:

URL: https://cgit.FreeBSD.org/src/commit/?id=deaa609d065d525a13392d09057afa237fbe4d68

commit deaa609d065d525a13392d09057afa237fbe4d68
Author:     Jamie Gritton <jamie@FreeBSD.org>
AuthorDate: 2025-09-13 22:30:14 +0000
Commit:     Jamie Gritton <jamie@FreeBSD.org>
CommitDate: 2025-09-15 03:34:00 +0000

    jaildesc: remove desc from the sysctl parameter list
    
    Like lastjid, desc should count as a pseudo-parameter.  The difference
    lies entirely in the security.jail.param sysctls, which list all of
    the jail parameters.  Since desc opens and returns a file descriptor,
    it has no place in such uses as "jls all."  Like lastjid, it's still
    recognized by the kernel if passed in/out, and hard-coded into libjail
    so it can be recognized there.
    
    (cherry picked from commit e75dda31c1eead9ad40580bd8fec17f2bbf55a21)
---
 lib/libjail/jail.c   | 10 +++++++++-
 sys/kern/kern_jail.c |  1 -
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/libjail/jail.c b/lib/libjail/jail.c
index f761bc6993e5..ad3348af0d2d 100644
--- a/lib/libjail/jail.c
+++ b/lib/libjail/jail.c
@@ -920,13 +920,21 @@ jailparam_type(struct jailparam *jp)
 	} desc;
 	int mib[CTL_MAXNAME];
 
-	/* The "lastjid" parameter isn't real. */
+	/*
+	 * Some pseudo-parameters don't show up in the sysctl
+	 * parameter list.
+	 */
 	name = jp->jp_name;
 	if (!strcmp(name, "lastjid")) {
 		jp->jp_valuelen = sizeof(int);
 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
 		return (0);
 	}
+	if (!strcmp(name, "desc")) {
+		jp->jp_valuelen = sizeof(int);
+		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_RW;
+		return (0);
+	}
 
 	/* Find the sysctl that describes the parameter. */
 	mib[0] = 0;
diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index 43035dc009b3..a75ba89d2a7e 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -4935,7 +4935,6 @@ sysctl_jail_param(SYSCTL_HANDLER_ARGS)
  * jail creation time but cannot be changed in an existing jail.
  */
 SYSCTL_JAIL_PARAM(, jid, CTLTYPE_INT | CTLFLAG_RDTUN, "I", "Jail ID");
-SYSCTL_JAIL_PARAM(, desc, CTLTYPE_INT | CTLFLAG_RW, "I", "Jail descriptor");
 SYSCTL_JAIL_PARAM(, parent, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail parent ID");
 SYSCTL_JAIL_PARAM_STRING(, name, CTLFLAG_RW, MAXHOSTNAMELEN, "Jail name");
 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");