[PATCH] client leaks ssh context, host_arg and packet.c leaks kex-structure.

Markus Schmidt markus at blueflash.cc
Tue Feb 5 21:44:43 AEDT 2019



After completing the session, the client leaks the ssh structure and the 
host_arg.

Also, on cleanup, packet.c leaks the kex-structure (which is held inside 
the ssh struct).

I've also moved host_arg from global to local variable, because it is 
only passed to one function.

Patch is attached

Best regards


Markus Schmidt
-------------- next part --------------
diff --git a/packet.c b/packet.c
index ec03301..d140a13 100644
--- a/packet.c
+++ b/packet.c
@@ -588,7 +588,7 @@ ssh_packet_close_internal(struct ssh *ssh, int do_close)
 	struct session_state *state = ssh->state;
 	u_int mode;
 
-	if (!state->initialized)
+	if (state!=NULL || !state->initialized)
 		return;
 	state->initialized = 0;
 	if (do_close) {
@@ -638,6 +638,10 @@ ssh_packet_close_internal(struct ssh *ssh, int do_close)
 	cipher_free(state->receive_context);
 	state->send_context = state->receive_context = NULL;
 	if (do_close) {
+		if (ssh->kex) {
+			kex_free(ssh->kex);
+			ssh->kex = NULL;
+		}
 		free(ssh->local_ipaddr);
 		ssh->local_ipaddr = NULL;
 		free(ssh->remote_ipaddr);
diff --git a/ssh.c b/ssh.c
index 91e7c35..a040204 100644
--- a/ssh.c
+++ b/ssh.c
@@ -169,7 +169,7 @@ char *host;
 
 /* Various strings used to to percent_expand() arguments */
 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
-static char uidstr[32], *host_arg, *conn_hash_hex;
+static char uidstr[32], *conn_hash_hex;
 
 /* socket address the host resolves to */
 struct sockaddr_storage hostaddr;
@@ -207,7 +207,7 @@ usage(void)
 	exit(255);
 }
 
-static int ssh_session2(struct ssh *, struct passwd *);
+static int ssh_session2(struct ssh *, struct passwd *, char *host_arg);
 static void load_public_identity_files(struct passwd *);
 static void main_sigchld_handler(int);
 
@@ -584,7 +584,7 @@ main(int ac, char **av)
 	struct ssh *ssh = NULL;
 	int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
 	int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
-	char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile;
+	char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile, *host_arg;
 	char cname[NI_MAXHOST];
 	struct stat st;
 	struct passwd *pw;
@@ -1523,8 +1523,12 @@ main(int ac, char **av)
 	}
 
  skip_connect:
-	exit_status = ssh_session2(ssh, pw);
+	exit_status = ssh_session2(ssh, pw, host_arg);
 	ssh_packet_close(ssh);
+	free(ssh);
+	ssh = NULL;
+	free(host_arg);
+	host_arg = NULL;
 
 	if (options.control_path != NULL && muxserver_sock != -1)
 		unlink(options.control_path);
@@ -1873,7 +1877,7 @@ ssh_session2_open(struct ssh *ssh)
 }
 
 static int
-ssh_session2(struct ssh *ssh, struct passwd *pw)
+ssh_session2(struct ssh *ssh, struct passwd *pw, char *host_arg)
 {
 	int r, devnull, id = -1;
 	char *cp, *tun_fwd_ifname = NULL;



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