Fix rtsold(8) remote buffer overflow vulnerability. [SA-14:20]

Fix memory leak in sandboxed namei lookup. [SA-14:22]

2 files changed, 18 insertions, 26 deletions

diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c
index 3671117..c85f9ed 100644
--- a/sys/kern/vfs_lookup.c
+++ b/sys/kern/vfs_lookup.c
@@ -121,6 +121,16 @@ TUNABLE_INT("vfs.lookup_shared", &lookup_shared);
  *		if symbolic link, massage name in buffer and continue
  *	}
  */
+static void
+namei_cleanup_cnp(struct componentname *cnp)
+{
+	uma_zfree(namei_zone, cnp->cn_pnbuf);
+#ifdef DIAGNOSTIC
+	cnp->cn_pnbuf = NULL;
+	cnp->cn_nameptr = NULL;
+#endif
+}
+
 int
 namei(struct nameidata *ndp)
 {
@@ -185,11 +195,7 @@ namei(struct nameidata *ndp)
 	}
 #endif
 	if (error) {
-		uma_zfree(namei_zone, cnp->cn_pnbuf);
-#ifdef DIAGNOSTIC
-		cnp->cn_pnbuf = NULL;
-		cnp->cn_nameptr = NULL;
-#endif
+		namei_cleanup_cnp(cnp);
 		ndp->ni_vp = NULL;
 		return (error);
 	}
@@ -256,11 +262,7 @@ namei(struct nameidata *ndp)
 			}
 		}
 		if (error) {
-			uma_zfree(namei_zone, cnp->cn_pnbuf);
-#ifdef DIAGNOSTIC
-			cnp->cn_pnbuf = NULL;
-			cnp->cn_nameptr = NULL;
-#endif
+			namei_cleanup_cnp(cnp);
 			return (error);
 		}
 	}
@@ -286,6 +288,7 @@ namei(struct nameidata *ndp)
 				if (KTRPOINT(curthread, KTR_CAPFAIL))
 					ktrcapfail(CAPFAIL_LOOKUP, NULL, NULL);
 #endif
+				namei_cleanup_cnp(cnp);
 				return (ENOTCAPABLE);
 			}
 			while (*(cnp->cn_nameptr) == '/') {
@@ -298,11 +301,7 @@ namei(struct nameidata *ndp)
 		ndp->ni_startdir = dp;
 		error = lookup(ndp);
 		if (error) {
-			uma_zfree(namei_zone, cnp->cn_pnbuf);
-#ifdef DIAGNOSTIC
-			cnp->cn_pnbuf = NULL;
-			cnp->cn_nameptr = NULL;
-#endif
+			namei_cleanup_cnp(cnp);
 			SDT_PROBE(vfs, namei, lookup, return, error, NULL, 0,
 			    0, 0);
 			return (error);
@@ -312,11 +311,7 @@ namei(struct nameidata *ndp)
 		 */
 		if ((cnp->cn_flags & ISSYMLINK) == 0) {
 			if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) {
-				uma_zfree(namei_zone, cnp->cn_pnbuf);
-#ifdef DIAGNOSTIC
-				cnp->cn_pnbuf = NULL;
-				cnp->cn_nameptr = NULL;
-#endif
+				namei_cleanup_cnp(cnp);
 			} else
 				cnp->cn_flags |= HASBUF;
 
@@ -378,11 +373,7 @@ namei(struct nameidata *ndp)
 		vput(ndp->ni_vp);
 		dp = ndp->ni_dvp;
 	}
-	uma_zfree(namei_zone, cnp->cn_pnbuf);
-#ifdef DIAGNOSTIC
-	cnp->cn_pnbuf = NULL;
-	cnp->cn_nameptr = NULL;
-#endif
+	namei_cleanup_cnp(cnp);
 	vput(ndp->ni_vp);
 	ndp->ni_vp = NULL;
 	vrele(ndp->ni_dvp);
diff --git a/usr.sbin/rtsold/rtsol.c b/usr.sbin/rtsold/rtsol.c
index c9b3d44..118206a 100644
--- a/usr.sbin/rtsold/rtsol.c
+++ b/usr.sbin/rtsold/rtsol.c
@@ -933,7 +933,8 @@ dname_labeldec(char *dst, size_t dlen, const char *src)
 	dst_origin = dst;
 	memset(dst, '\0', dlen);
 	while (src && (len = (uint8_t)(*src++) & 0x3f) &&
-	    (src + len) <= src_last) {
+	    (src + len) <= src_last &&
+	    (dst - dst_origin < (ssize_t)dlen)) {
 		if (dst != dst_origin)
 			*dst++ = '.';
 		warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);