MFC r292277:

  Fix jail name checking that disallowed anything that starts with '0'.
  The intention was to just limit leading zeroes on numeric names.  That
  check is now improved to also catch the leading spaces and '+' that
  strtoul can pass through.

PR:		204897

1 files changed, 6 insertions, 3 deletions

diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
index af5feb3..42c53c0 100644
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -1585,11 +1585,14 @@ kern_jail_set(struct thread *td, struct uio *optuio, int flags)
 #endif
 	onamelen = namelen = 0;
 	if (name != NULL) {
-		/* Give a default name of the jid. */
+		/* Give a default name of the jid.  Also allow the name to be
+		 * explicitly the jid - but not any other number, and only in
+		 * normal form (no leading zero/etc).
+		 */
 		if (name[0] == '\0')
 			snprintf(name = numbuf, sizeof(numbuf), "%d", jid);
-		else if (*namelc == '0' || (strtoul(namelc, &p, 10) != jid &&
-		    *p == '\0')) {
+		else if ((strtoul(namelc, &p, 10) != jid ||
+			  namelc[0] < '1' || namelc[0] > '9') && *p == '\0') {
 			error = EINVAL;
 			vfs_opterror(opts,
 			    "name cannot be numeric (unless it is the jid)");