TLS: fix another use-of-uninitialized-value error in ClientHello pars…

…ing (#1179) Error detected with valgrind. ==13127== Conditional jump or move depends on uninitialised value(s) ==13127== at 0x483EF58: strlen (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so) ==13127== by 0x1A93B6: ndpi_strdup (ndpi_main.c:159) ==13127== by 0x1C07CC: processClientServerHello (tls.c:1678) ==13127== by 0x1C0C4C: processTLSBlock (tls.c:712) ==13127== by 0x1C0C4C: ndpi_search_tls_tcp.part.0 (tls.c:849) See also 8c3674e
ntop · May 9, 2021 · 12c6ab7 · 12c6ab7
1 parent 8c28613
commit 12c6ab7
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Showing 3 changed files with 6 additions and 2 deletions.
diff --git a/src/lib/protocols/tls.c b/src/lib/protocols/tls.c
@@ -1687,7 +1687,8 @@ int processClientServerHello(struct ndpi_detection_module_struct *ndpi_struct,
 		while(s_offset < tot_alpn_len && s_offset < total_len) {
 		  u_int8_t alpn_i, alpn_len = packet->payload[s_offset++];
 
-		  if((s_offset + alpn_len) <= tot_alpn_len) {
+		  if((s_offset + alpn_len) <= tot_alpn_len &&
+		     (s_offset + alpn_len) <= total_len) {
 #ifdef DEBUG_TLS
 		    printf("Client TLS [ALPN: %u]\n", alpn_len);
 #endif

diff --git a/tests/pcap/tls_invalid_reads.pcap b/tests/pcap/tls_invalid_reads.pcap
diff --git a/tests/result/tls_invalid_reads.pcap.out b/tests/result/tls_invalid_reads.pcap.out
@@ -1,8 +1,11 @@
 TLS	8	1891	2
+Amazon	3	560	1
 
 JA3 Host Stats: 
 		 IP Address                  	 # JA3C     
+	1	 10.191.139.17            	 1      
 
 
 	1	TCP 192.168.10.101:3967 <-> 206.33.61.113:443 [proto: 91/TLS][cat: Web/5][4 pkts/330 bytes <-> 3 pkts/1497 bytes][Goodput ratio: 31/89][0.08 sec][bytes ratio: -0.639 (Download)][IAT c2s/s2c min/avg/max/stddev: 0/38 25/19 58/38 24/19][Pkt Len c2s/s2c min/avg/max/stddev: 54/60 82/499 156/905 43/346][Risk: ** Obsolete TLS version (< 1.1) **][TLSv1][JA3S: 53611273a714cb4789c8222932efd5a7 (INSECURE)][Cipher: TLS_RSA_WITH_RC4_128_MD5][Plen Bins: 0,0,0,33,0,0,0,0,0,0,0,0,0,0,33,0,0,0,0,0,0,0,0,0,0,0,33,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
-	2	TCP 74.80.160.99:3258 -> 67.217.77.28:443 [proto: 91/TLS][cat: Web/5][1 pkts/64 bytes -> 0 pkts/0 bytes][Goodput ratio: 15/0][< 1 sec][Plen Bins: 100,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
+	2	TCP 10.191.139.17:58552 <-> 54.221.224.45:443 [VLAN: 2][proto: GTP:91.178/TLS.Amazon][cat: Web/5][2 pkts/442 bytes <-> 1 pkts/118 bytes][Goodput ratio: 41/0][0.23 sec][ALPN: ][TLSv1.2][Client: e.crashlytics.com][JA3C: 5f704e1e0a47641621b22177875f4e85][PLAIN TEXT (e.crashlytics.com)][Plen Bins: 0,0,0,0,0,100,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
+	3	TCP 74.80.160.99:3258 -> 67.217.77.28:443 [proto: 91/TLS][cat: Web/5][1 pkts/64 bytes -> 0 pkts/0 bytes][Goodput ratio: 15/0][< 1 sec][Plen Bins: 100,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]