# HG changeset patch # User Matt Johnston # Date 1322947885 -28800 # Node ID 818108bf7749bfecd4715a30e2583aac9dbe25e8 # Parent 5e8d84f3ee7256d054ecf7e9f248765ccaa7f24f - Fix use-after-free if multiple command requests were sent. Move the original_command into chansess struct since that makes more sense --- a/auth.h +++ b/auth.h @@ -133,7 +133,6 @@ struct PubKeyOptions { int no_pty_flag; /* "command=" option. */ unsigned char * forced_command; - unsigned char * original_command; }; #endif --- a/chansession.h +++ b/chansession.h @@ -69,6 +69,10 @@ struct ChanSess { char * agentfile; char * agentdir; #endif + +#ifdef ENABLE_SVR_PUBKEY_OPTIONS + char *original_command; +#endif }; struct ChildPid { --- a/svr-authpubkeyoptions.c +++ b/svr-authpubkeyoptions.c @@ -92,14 +92,15 @@ int svr_pubkey_allows_pty() { * by any 'command' public key option. */ void svr_pubkey_set_forced_command(struct ChanSess *chansess) { if (ses.authstate.pubkey_options) { - ses.authstate.pubkey_options->original_command = chansess->cmd; - if (!chansess->cmd) - { - ses.authstate.pubkey_options->original_command = m_strdup(""); + if (chansess->cmd) { + /* original_command takes ownership */ + chansess->original_command = chansess->cmd; + } else { + chansess->original_command = m_strdup(""); } - chansess->cmd = ses.authstate.pubkey_options->forced_command; + chansess->cmd = m_strdup(ses.authstate.pubkey_options->forced_command); #ifdef LOG_COMMANDS - dropbear_log(LOG_INFO, "Command forced to '%s'", ses.authstate.pubkey_options->original_command); + dropbear_log(LOG_INFO, "Command forced to '%s'", chansess->original_command); #endif } } --- a/svr-chansession.c +++ b/svr-chansession.c @@ -217,6 +217,8 @@ static int newchansess(struct Channel *c struct ChanSess *chansess; + TRACE(("new chansess %p", channel)) + dropbear_assert(channel->typedata == NULL); chansess = (struct ChanSess*)m_malloc(sizeof(struct ChanSess)); @@ -279,6 +281,10 @@ static void closechansess(struct Channel m_free(chansess->cmd); m_free(chansess->term); +#ifdef ENABLE_SVR_PUBKEY_OPTIONS + m_free(chansess->original_command); +#endif + if (chansess->tty) { /* write the utmp/wtmp login record */ li = chansess_login_alloc(chansess); @@ -924,10 +930,8 @@ static void execchild(void *user_data) { } #ifdef ENABLE_SVR_PUBKEY_OPTIONS - if (ses.authstate.pubkey_options && - ses.authstate.pubkey_options->original_command) { - addnewvar("SSH_ORIGINAL_COMMAND", - ses.authstate.pubkey_options->original_command); + if (chansess->original_command) { + addnewvar("SSH_ORIGINAL_COMMAND", chansess->original_command); } #endif