o Introduce pr_mtx into struct prison, providing protection for the

  mutable contents of struct prison (hostname, securelevel, refcount,
  pr_linux, ...)
o Generally introduce mtx_lock()/mtx_unlock() calls throughout kern/
  so as to enforce these protections, in particular, in kern_mib.c
  protection sysctl access to the hostname and securelevel, as well as
  kern_prot.c access to the securelevel for access control purposes.
o Rewrite linux emulator abstractions for accessing per-jail linux
  mib entries (osname, osrelease, osversion) so that they don't return
  a pointer to the text in the struct linux_prison, rather, a copy
  to an array passed into the calls.  Likewise, update linprocfs to
  use these primitives.
o Update in_pcb.c to always use prison_getip() rather than directly
  accessing struct prison.

Reviewed by:	jhb

1 files changed, 7 insertions, 4 deletions

diff --git a/sys/fs/procfs/procfs_status.c b/sys/fs/procfs/procfs_status.c
index ee5cc7b..6dd34c7 100644
--- a/sys/fs/procfs/procfs_status.c
+++ b/sys/fs/procfs/procfs_status.c
@@ -43,10 +43,10 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/exec.h>
-#include <sys/jail.h>
 #include <sys/lock.h>
-#include <sys/malloc.h>
 #include <sys/mutex.h>
+#include <sys/jail.h>
+#include <sys/malloc.h>
 #include <sys/proc.h>
 #include <sys/resourcevar.h>
 #include <sys/tty.h>
@@ -178,11 +178,14 @@ procfs_dostatus(curp, p, pfs, uio)
 		DOCHECK();
 	}
 
-	if (jailed(p->p_ucred))
+	if (jailed(p->p_ucred)) {
+		mtx_lock(&p->p_ucred->cr_prison->pr_mtx);
 		ps += snprintf(ps, psbuf + sizeof(psbuf) - ps,
 		    " %s", p->p_ucred->cr_prison->pr_host);
-	else
+		mtx_unlock(&p->p_ucred->cr_prison->pr_mtx);
+	} else {
 		ps += snprintf(ps, psbuf + sizeof(psbuf) - ps, " -");
+	}
 	DOCHECK();
 	ps += snprintf(ps, psbuf + sizeof(psbuf) - ps, "\n");
 	DOCHECK();