diff options
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | socket.c | 38 |
2 files changed, 30 insertions, 12 deletions
@@ -112,6 +112,10 @@ fetchmail-6.4.22 (not yet released): command continuation) * On IMAP connections, When --auth external is requested but not advertised by the server, log a proper error message. +* Fetchmail no longer crashes when attempting a connection with --plugin "" or + --plugout "". +* Fetchmail no longer leaks memory when processing the arguments of --plugin or + --plugout on connections. # CHANGES: * IMAP: When fetchmail is in not-authenticated state and the server volunteers @@ -82,7 +82,20 @@ extern int h_errno; #endif /* ndef h_errno */ #ifdef HAVE_SOCKETPAIR -static char *const *parse_plugin(const char *plugin, const char *host, const char *service) +static void free_plugindata(char **argvec) +{ + if (argvec) { + xfree(*argvec); + xfree(argvec); + } +} + +/** parse plugin and interpolate %h and %p with single-quoted host and service. + * Returns a malloc()ed pointer to a NULL-terminated vector of pointers, of + * which the first is also malloc()ed and the 2nd and later ones (if present) + * are pointers into the same memory region - these serve as input for the + * argument vector of execvp() in handle_plugin. */ +static char **parse_plugin(const char *plugin, const char *host, const char *service) { char **argvec; const char *c, *p; @@ -106,12 +119,7 @@ static char *const *parse_plugin(const char *plugin, const char *host, const cha /* we need to discount 2 bytes for each placeholder */ plugin_copy_len = plugin_len + (host_len - 2) * host_count + (service_len - 2) * service_count; - plugin_copy = (char *)malloc(plugin_copy_len + 1); - if (!plugin_copy) - { - report(stderr, GT_("fetchmail: malloc failed\n")); - return NULL; - } + plugin_copy = (char *)xmalloc(plugin_copy_len + 1); while (plugin_offset < plugin_len && plugin_copy_offset < plugin_copy_len) { if ((plugin[plugin_offset] == '%') && (plugin[plugin_offset + 1] == 'h')) @@ -142,6 +150,7 @@ static char *const *parse_plugin(const char *plugin, const char *host, const cha return NULL; } memset(argvec, 0, vecsiz); + argvec[0] = plugin_copy; /* make sure we can free() it in every case */ for (p = cp = plugin_copy, i = 0; *cp; cp++) { if ((!isspace((unsigned char)*cp)) && (cp == p ? 1 : isspace((unsigned char)*p))) { argvec[i] = cp; @@ -161,21 +170,29 @@ static int handle_plugin(const char *host, /* get a socket mediated through a given external command */ { int fds[2]; - char *const *argvec; + char **argvec; /* * The author of this code, Felix von Leitner <felix@convergence.de>, says: * he chose socketpair() instead of pipe() because socketpair creates * bidirectional sockets while allegedly some pipe() implementations don't. */ + argvec = parse_plugin(plugin,host,service); + if (!argvec || !*argvec[0]) { + free_plugindata(argvec); + report(stderr, GT_("fetchmail: plugin for host %s service %s is empty, cannot run!\n"), host, service); + return -1; + } if (socketpair(AF_UNIX,SOCK_STREAM,0,fds)) { report(stderr, GT_("fetchmail: socketpair failed\n")); + free_plugindata(argvec); return -1; } switch (fork()) { case -1: /* error */ + free_plugindata(argvec); report(stderr, GT_("fetchmail: fork failed\n")); return -1; case 0: /* child */ @@ -190,15 +207,12 @@ static int handle_plugin(const char *host, (void) close(fds[0]); if (outlevel >= O_VERBOSE) report(stderr, GT_("running %s (host %s service %s)\n"), plugin, host, service); - argvec = parse_plugin(plugin,host,service); - if (argvec == NULL) - _exit(EXIT_FAILURE); execvp(*argvec, argvec); report(stderr, GT_("execvp(%s) failed\n"), *argvec); _exit(EXIT_FAILURE); break; default: /* parent */ - /* NOP */ + free_plugindata(argvec); break; } /* fds[0] is the child's end; close it for proper EOF detection */ |