Plug memory leaks from pcap_ether_hostton().

pcap_ether_hostton() returns a pointer to allocated memory, which needs
to be freed, which gen_scode() does for the successful case only.  To
have the memory freed in any case, copy the value into a local variable
and free the allocated memory immediately thereafter -- this suffices
since the data size is fixed and the value needs to be used only once
per code path.  In other words, apply the solution from commit 2b01095
to the problem from commit bcbef22.

diff --git a/gencode.c b/gencode.c
index ec2bf86e285ab3c593dd8e0555138d7b4724d98d..172a9658062781affc3a258003ef396879bdb434 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -6739,7 +6739,8 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
        int proto = q.proto;
        int dir = q.dir;
        int tproto;
-       u_char *eaddr;
+       u_char *eaddrp;
+       u_char eaddr[6];
        bpf_u_int32 mask, addr;
        struct addrinfo *res, *res0;
        struct sockaddr_in *sin4;
@@ -6781,33 +6782,36 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
                        case DLT_EN10MB:
                        case DLT_NETANALYZER:
                        case DLT_NETANALYZER_TRANSPARENT:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
+                               eaddrp = pcap_ether_hostton(name);
+                               if (eaddrp == NULL)
                                        bpf_error(cstate,
                                            "unknown ether host '%s'", name);
+                               memcpy(eaddr, eaddrp, sizeof(eaddr));
+                               free(eaddrp);
                                tmp = gen_prevlinkhdr_check(cstate);
                                b = gen_ehostop(cstate, eaddr, dir);
                                if (tmp != NULL)
                                        gen_and(tmp, b);
-                               free(eaddr);
                                return b;
 
                        case DLT_FDDI:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
+                               eaddrp = pcap_ether_hostton(name);
+                               if (eaddrp == NULL)
                                        bpf_error(cstate,
                                            "unknown FDDI host '%s'", name);
+                               memcpy(eaddr, eaddrp, sizeof(eaddr));
+                               free(eaddrp);
                                b = gen_fhostop(cstate, eaddr, dir);
-                               free(eaddr);
                                return b;
 
                        case DLT_IEEE802:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
+                               eaddrp = pcap_ether_hostton(name);
+                               if (eaddrp == NULL)
                                        bpf_error(cstate,
                                            "unknown token ring host '%s'", name);
+                               memcpy(eaddr, eaddrp, sizeof(eaddr));
+                               free(eaddrp);
                                b = gen_thostop(cstate, eaddr, dir);
-                               free(eaddr);
                                return b;
 
                        case DLT_IEEE802_11:
@@ -6815,21 +6819,23 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
                        case DLT_IEEE802_11_RADIO_AVS:
                        case DLT_IEEE802_11_RADIO:
                        case DLT_PPI:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
+                               eaddrp = pcap_ether_hostton(name);
+                               if (eaddrp == NULL)
                                        bpf_error(cstate,
                                            "unknown 802.11 host '%s'", name);
+                               memcpy(eaddr, eaddrp, sizeof(eaddr));
+                               free(eaddrp);
                                b = gen_wlanhostop(cstate, eaddr, dir);
-                               free(eaddr);
                                return b;
 
                        case DLT_IP_OVER_FC:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
+                               eaddrp = pcap_ether_hostton(name);
+                               if (eaddrp == NULL)
                                        bpf_error(cstate,
                                            "unknown Fibre Channel host '%s'", name);
+                               memcpy(eaddr, eaddrp, sizeof(eaddr));
+                               free(eaddrp);
                                b = gen_ipfchostop(cstate, eaddr, dir);
-                               free(eaddr);
                                return b;
                        }
 
@@ -6989,9 +6995,11 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 
        case Q_GATEWAY:
 #ifndef INET6
-               eaddr = pcap_ether_hostton(name);
-               if (eaddr == NULL)
+               eaddrp = pcap_ether_hostton(name);
+               if (eaddrp == NULL)
                        bpf_error(cstate, "unknown ether host: %s", name);
+               memcpy(eaddr, eaddrp, sizeof(eaddr));
+               free(eaddrp);
 
                res = pcap_nametoaddrinfo(name);
                cstate->ai = res;
@@ -7000,7 +7008,6 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
                b = gen_gateway(cstate, eaddr, res, proto);
                cstate->ai = NULL;
                freeaddrinfo(res);
-               free(eaddr);
                if (b == NULL)
                        bpf_error(cstate, "unknown host '%s'", name);
                return b;