2 files changed, 21 insertions, 5 deletions

diff --git a/usr.bin/fstat/fstat.1 b/usr.bin/fstat/fstat.1
index 01143ab7c6d9..55ac95bcaa8d 100644
--- a/usr.bin/fstat/fstat.1
+++ b/usr.bin/fstat/fstat.1
@@ -51,8 +51,8 @@ The
 .Nm
 utility identifies open files.
 A file is considered open by a process if it was explicitly opened,
-is the working directory, root directory, active executable text, or kernel
-trace file for that process.
+is the working directory, root directory, jail root directory,
+active executable text, or kernel trace file for that process.
 If no options are specified,
 .Nm
 reports on all open files in the system.
@@ -121,11 +121,12 @@ The file number in the per-process open file table or one of the following
 special names:
 .Pp
 .Bd -literal -offset indent -compact
-text	- executable text inode
-wd 	- current working directory
+jail	- jail root directory
+mmap	- memory-mapped file
 root	- root inode
+text	- executable text inode
 tr	- kernel trace file
-mmap	- memory-mapped file
+wd 	- current working directory
 .Ed
 .Pp
 If the file number is followed by an asterisk (``*''), the file is
diff --git a/usr.bin/fstat/fstat.c b/usr.bin/fstat/fstat.c
index a20469e63742..86eee92acfdc 100644
--- a/usr.bin/fstat/fstat.c
+++ b/usr.bin/fstat/fstat.c
@@ -106,6 +106,7 @@ __FBSDID("$FreeBSD$");
 #define	RDIR	-3
 #define	TRACE	-4
 #define	MMAP	-5
+#define	JDIR	-6
 
 DEVS *devs;
 
@@ -309,6 +310,9 @@ int	Pid;
 	case MMAP: \
 		printf(" mmap"); \
 		break; \
+	case JDIR: \
+		printf(" jail"); \
+		break; \
 	default: \
 		printf(" %4d", i); \
 		break; \
@@ -345,6 +349,11 @@ dofiles(struct kinfo_proc *kp)
 	 */
 	vtrans(filed.fd_cdir, CDIR, FREAD);
 	/*
+	 * jail root, if any.
+	 */
+	if (filed.fd_jdir)
+		vtrans(filed.fd_jdir, JDIR, FREAD);
+	/*
 	 * ktrace vnode, if one
 	 */
 	if (kp->ki_tracep)
@@ -358,6 +367,12 @@ dofiles(struct kinfo_proc *kp)
 	 * open files
 	 */
 #define FPSIZE	(sizeof (struct file *))
+#define MAX_LASTFILE	(0x1000000)
+
+	/* Sanity check on filed.fd_lastfile */
+	if (filed.fd_lastfile <= -1 || filed.fd_lastfile > MAX_LASTFILE)
+		return;
+
 	ALLOC_OFILES(filed.fd_lastfile+1);
 	if (!KVM_READ(filed.fd_ofiles, ofiles,
 	    (filed.fd_lastfile+1) * FPSIZE)) {