From 108217f4bb1afb8b25fc705c2722b3e328b1ad78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Valverde?= <j@v6e.pt>
Date: Sat, 16 Sep 2023 06:59:12 +0100
Subject: [PATCH] addr_resolv: Fix a heap buffer overflow

Make sure we always pass at least 6 bytes to ws_manuf_lookup_str().

Fixes #19344.
---
 epan/addr_resolv.c   | 29 +++++++++++++++++++++--------
 epan/addr_resolv.h   |  4 ++--
 epan/address_types.c |  4 ++--
 3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/epan/addr_resolv.c b/epan/addr_resolv.c
index 3e0cc6d..4a6be03 100644
--- a/epan/addr_resolv.c
+++ b/epan/addr_resolv.c
@@ -1607,12 +1607,16 @@ add_manuf_name(const guint8 *addr, unsigned int mask, gchar *name, gchar *longna
 } /* add_manuf_name */
 
 static hashmanuf_t *
-manuf_name_lookup(const guint8 *addr)
+manuf_name_lookup(const guint8 *addr, size_t size)
 {
     guint32       manuf_key;
     guint8       oct;
     hashmanuf_t  *manuf_value;
 
+    if (size < 6) {
+        return NULL;
+    }
+
     /* manuf needs only the 3 most significant octets of the ethernet address */
     manuf_key = addr[0];
     manuf_key = manuf_key<<8;
@@ -1773,6 +1777,7 @@ eth_addr_resolve(hashether_t *tp) {
     ether_t      *eth;
     hashmanuf_t *manuf_value;
     const guint8 *addr = tp->addr;
+    size_t addr_size = sizeof(tp->addr);
 
     if ( (eth = get_ethbyaddr(addr)) != NULL) {
         (void) g_strlcpy(tp->resolved_name, eth->name, MAXNAMELEN);
@@ -1819,7 +1824,7 @@ eth_addr_resolve(hashether_t *tp) {
         } while (mask--);
 
         /* Now try looking in the manufacturer table. */
-        manuf_value = manuf_name_lookup(addr);
+        manuf_value = manuf_name_lookup(addr, addr_size);
         if ((manuf_value != NULL) && (manuf_value->status != HASHETHER_STATUS_UNRESOLVED)) {
             g_snprintf(tp->resolved_name, MAXNAMELEN, "%s_%02x:%02x:%02x",
                     manuf_value->resolved_name, addr[3], addr[4], addr[5]);
@@ -3378,11 +3383,11 @@ get_vlan_name(wmem_allocator_t *allocator, const guint16 id)
 } /* get_vlan_name */
 
 const gchar *
-get_manuf_name(const guint8 *addr)
+get_manuf_name(const guint8 *addr, size_t size)
 {
     hashmanuf_t *manuf_value;
 
-    manuf_value = manuf_name_lookup(addr);
+    manuf_value = manuf_name_lookup(addr, size);
     if (gbl_resolv_flags.mac_name && manuf_value->status != HASHETHER_STATUS_UNRESOLVED)
         return manuf_value->resolved_name;
 
@@ -3393,16 +3398,22 @@ get_manuf_name(const guint8 *addr)
 const gchar *
 tvb_get_manuf_name(tvbuff_t *tvb, gint offset)
 {
-    return get_manuf_name(tvb_get_ptr(tvb, offset, 3));
+    guint8 buf[6] = { 0 };
+    tvb_memcpy(tvb, buf, offset, 3);
+    return get_manuf_name(buf, sizeof(buf));
 }
 
 const gchar *
-get_manuf_name_if_known(const guint8 *addr)
+get_manuf_name_if_known(const guint8 *addr, size_t size)
 {
     hashmanuf_t *manuf_value;
     guint manuf_key;
     guint8 oct;
 
+    if (size != 6) {
+        return NULL;
+    }
+
     /* manuf needs only the 3 most significant octets of the ethernet address */
     manuf_key = addr[0];
     manuf_key = manuf_key<<8;
@@ -3437,7 +3448,9 @@ uint_get_manuf_name_if_known(const guint manuf_key)
 const gchar *
 tvb_get_manuf_name_if_known(tvbuff_t *tvb, gint offset)
 {
-    return get_manuf_name_if_known(tvb_get_ptr(tvb, offset, 3));
+    guint8 buf[6] = { 0 };
+    tvb_memcpy(tvb, buf, offset, 3);
+    return get_manuf_name_if_known(buf, sizeof(buf));
 }
 
 char* get_hash_manuf_resolved_name(hashmanuf_t* manuf)
@@ -3455,7 +3468,7 @@ eui64_to_display(wmem_allocator_t *allocator, const guint64 addr_eui64)
     /* Copy and convert the address to network byte order. */
     *(guint64 *)(void *)(addr) = pntoh64(&(addr_eui64));
 
-    manuf_value = manuf_name_lookup(addr);
+    manuf_value = manuf_name_lookup(addr, 8);
     if (!gbl_resolv_flags.mac_name || (manuf_value->status == HASHETHER_STATUS_UNRESOLVED)) {
         ret = wmem_strdup_printf(allocator, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x", addr[0], addr[1], addr[2], addr[3], addr[4], addr[5], addr[6], addr[7]);
     } else {
diff --git a/epan/addr_resolv.h b/epan/addr_resolv.h
index 313e8f9..362682c 100644
--- a/epan/addr_resolv.h
+++ b/epan/addr_resolv.h
@@ -223,13 +223,13 @@ const gchar *get_ether_name_if_known(const guint8 *addr);
  * Given a sequence of 3 octets containing an OID, get_manuf_name()
  * returns the vendor name, or "%02x:%02x:%02x" if not known.
  */
-extern const gchar *get_manuf_name(const guint8 *addr);
+extern const gchar *get_manuf_name(const guint8 *addr, size_t size);
 
 /*
  * Given a sequence of 3 octets containing an OID, get_manuf_name_if_known()
  * returns the vendor name, or NULL if not known.
  */
-WS_DLL_PUBLIC const gchar *get_manuf_name_if_known(const guint8 *addr);
+WS_DLL_PUBLIC const gchar *get_manuf_name_if_known(const guint8 *addr, size_t size);
 
 /*
  * Given an integer containing a 24-bit OID, uint_get_manuf_name_if_known()
diff --git a/epan/address_types.c b/epan/address_types.c
index 86812af..776a02d 100644
--- a/epan/address_types.c
+++ b/epan/address_types.c
@@ -382,7 +382,7 @@ static const gchar* fcwwn_name_res_str(const address* addr)
     case FC_NH_NAA_IEEE_E:
 
         memcpy (oui, &addrp[2], 6);
-        return get_manuf_name(oui);
+        return get_manuf_name(oui, sizeof(oui));
 
     case FC_NH_NAA_IEEE_R:
         oui[0] = ((addrp[0] & 0x0F) << 4) | ((addrp[1] & 0xF0) >> 4);
@@ -392,7 +392,7 @@ static const gchar* fcwwn_name_res_str(const address* addr)
         oui[4] = ((addrp[4] & 0x0F) << 4) | ((addrp[5] & 0xF0) >> 4);
         oui[5] = ((addrp[5] & 0x0F) << 4) | ((addrp[6] & 0xF0) >> 4);
 
-        return get_manuf_name(oui);
+        return get_manuf_name(oui, sizeof(oui));
     }
 
     return "";
-- 
2.33.0