--- Linux-PAM-0.99.6.2/modules/pam_namespace/pam_namespace.h.temp-logon 2007-05-31 17:04:17.000000000 +0200 +++ Linux-PAM-0.99.6.2/modules/pam_namespace/pam_namespace.h 2007-05-31 17:04:18.000000000 +0200 @@ -90,6 +90,7 @@ #define PAMNS_NO_UNMOUNT_ON_CLOSE 0x00010000 /* no unmount at session close */ #define NAMESPACE_MAX_DIR_LEN 80 +#define NAMESPACE_POLYDIR_DATA "pam_namespace:polydir_data" /* * Polyinstantiation method options, based on user, security context @@ -100,6 +101,8 @@ USER, CONTEXT, LEVEL, + TMPDIR, + TMPFS }; /* @@ -128,6 +131,7 @@ enum polymethod method; /* method used to polyinstantiate */ unsigned int num_uids; /* number of override uids */ uid_t *uid; /* list of override uids */ + int exclusive; /* polyinstatiate exclusively for override uids */ struct polydir_s *next; /* pointer to the next polydir entry */ }; --- Linux-PAM-0.99.6.2/modules/pam_namespace/pam_namespace.c.temp-logon 2007-05-31 17:04:18.000000000 +0200 +++ Linux-PAM-0.99.6.2/modules/pam_namespace/pam_namespace.c 2007-05-31 17:54:14.000000000 +0200 @@ -43,6 +43,7 @@ strcpy(pent->instance_prefix, ent->instance_prefix); pent->method = ent->method; pent->num_uids = ent->num_uids; + pent->exclusive = ent->exclusive; if (ent->num_uids) { uid_t *pptr, *eptr; @@ -120,6 +121,10 @@ } } +static void cleanup_data(pam_handle_t *pamh, void *data, int err) +{ + del_polydir_list(data); +} /* * Called from parse_config_file, this function processes a single line @@ -140,6 +145,7 @@ poly.uid = NULL; poly.num_uids = 0; + poly.exclusive = 0; /* * skip the leading white space @@ -223,24 +229,13 @@ } /* - * Ensure that all pathnames are absolute path names. - */ - if ((dir[0] != '/') || (instance_prefix[0] != '/')) { - pam_syslog(idata->pamh, LOG_NOTICE,"Pathnames must start with '/'"); - goto skipping; - } - if (strstr(dir, "..") || strstr(instance_prefix, "..")) { - pam_syslog(idata->pamh, LOG_NOTICE,"Pathnames must not contain '..'"); - goto skipping; - } - - /* * Populate polyinstantiated directory structure with appropriate * pathnames and the method with which to polyinstantiate. */ if (strlen(dir) >= sizeof(poly.dir) || strlen(instance_prefix) >= sizeof(poly.instance_prefix)) { pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames too long"); + goto skipping; } strcpy(poly.dir, dir); strcpy(poly.instance_prefix, instance_prefix); @@ -248,6 +243,18 @@ poly.method = NONE; if (strcmp(method, "user") == 0) poly.method = USER; + + if (strcmp(method, "tmpdir") == 0) { + poly.method = TMPDIR; + if (sizeof(poly.instance_prefix) - strlen(poly.instance_prefix) < 7) { + pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames too long"); + goto skipping; + } + strcat(poly.instance_prefix, "XXXXXX"); + } + + if (strcmp(method, "tmpfs") == 0) + poly.method = TMPFS; #ifdef WITH_SELINUX if (strcmp(method, "level") == 0) { @@ -266,12 +273,24 @@ #endif - if ( poly.method == NONE) { + if (poly.method == NONE) { pam_syslog(idata->pamh, LOG_NOTICE, "Illegal method"); goto skipping; } /* + * Ensure that all pathnames are absolute path names. + */ + if ((dir[0] != '/') || (poly.method != TMPFS && instance_prefix[0] != '/')) { + pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames must start with '/'"); + goto skipping; + } + if (strstr(dir, "..") || strstr(instance_prefix, "..")) { + pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames must not contain '..'"); + goto skipping; + } + + /* * If the line in namespace.conf for a directory to polyinstantiate * contains a list of override users (users for whom polyinstantiation * is not performed), read the user ids, convert names into uids, and @@ -281,7 +300,11 @@ uid_t *uidptr; const char *ustr, *sstr; int count, i; - + + if (*uids == '~') { + poly.exclusive = 1; + uids++; + } for (count = 0, ustr = sstr = uids; sstr; ustr = sstr + 1, count++) sstr = strchr(ustr, ','); @@ -419,6 +442,7 @@ * directory's list of override uids. If the uid is one of the override * uids for the polyinstantiated directory, polyinstantiation is not * performed for that user for that directory. + * If exclusive is set the returned values are opposite. */ static int ns_override(struct polydir_s *polyptr, struct instance_data *idata, uid_t uid) @@ -432,11 +456,11 @@ for (i = 0; i < polyptr->num_uids; i++) { if (uid == polyptr->uid[i]) { - return 1; + return !polyptr->exclusive; } } - return 0; + return polyptr->exclusive; } /* @@ -622,6 +646,12 @@ #endif /* WITH_SELINUX */ + case TMPDIR: + case TMPFS: + if ((*i_name=strdup("")) == NULL) + goto fail; + return PAM_SUCCESS; + default: if (idata->flags & PAMNS_DEBUG) pam_syslog(idata->pamh, LOG_ERR, "Unknown method"); @@ -725,7 +755,7 @@ * execute it and pass directory to polyinstantiate and instance * directory as arguments. */ -static int inst_init(const struct polydir_s *polyptr, char *ipath, +static int inst_init(const struct polydir_s *polyptr, const char *ipath, struct instance_data *idata) { pid_t rc, pid; @@ -791,11 +821,11 @@ * Create polyinstantiated instance directory (ipath). */ #ifdef WITH_SELINUX -static int create_dirs(const struct polydir_s *polyptr, char *ipath, +static int create_dirs(struct polydir_s *polyptr, char *ipath, security_context_t icontext, security_context_t ocontext, struct instance_data *idata) #else -static int create_dirs(const struct polydir_s *polyptr, char *ipath, +static int create_dirs(struct polydir_s *polyptr, char *ipath, struct instance_data *idata) #endif { @@ -834,7 +864,17 @@ * attributes to match that of the original directory that is being * polyinstantiated. */ - if (mkdir(ipath, S_IRUSR) < 0) { + + if (polyptr->method == TMPDIR) { + if (mkdtemp(polyptr->instance_prefix) == NULL) { + pam_syslog(idata->pamh, LOG_ERR, "Error creating temporary instance %s, %m", + polyptr->instance_prefix); + polyptr->method = NONE; /* do not clean up! */ + return PAM_SESSION_ERR; + } + /* copy the actual directory name to ipath */ + strcpy(ipath, polyptr->instance_prefix); + } else if (mkdir(ipath, S_IRUSR) < 0) { if (errno == EEXIST) goto inst_init; else { @@ -920,13 +960,12 @@ * security attributes, and performs bind mount to setup the process * namespace. */ -static int ns_setup(const struct polydir_s *polyptr, +static int ns_setup(struct polydir_s *polyptr, struct instance_data *idata) { int retval = 0; char *inst_dir = NULL; char *instname = NULL; - char *dir; #ifdef WITH_SELINUX security_context_t instcontext = NULL, origcontext = NULL; #endif @@ -935,9 +974,15 @@ pam_syslog(idata->pamh, LOG_DEBUG, "Set namespace for directory %s", polyptr->dir); - dir = strrchr(polyptr->dir, '/'); - if (dir && strlen(dir) > 1) - dir++; + if (polyptr->method == TMPFS) { + if (mount("tmpfs", polyptr->dir, "tmpfs", 0, NULL) < 0) { + pam_syslog(idata->pamh, LOG_ERR, "Error mounting tmpfs on %s, %m", + polyptr->dir); + return PAM_SESSION_ERR; + } + /* we must call inst_init after the mount in this case */ + return inst_init(polyptr, "tmpfs", idata); + } /* * Obtain the name of instance pathname based on the @@ -1043,6 +1088,58 @@ return retval; } +static int cleanup_tmpdirs(struct instance_data *idata) +{ + struct polydir_s *pptr; + pid_t rc, pid; + sighandler_t osighand = NULL; + int status; + + osighand = signal(SIGCHLD, SIG_DFL); + if (osighand == SIG_ERR) { + pam_syslog(idata->pamh, LOG_ERR, "Cannot set signal value"); + rc = PAM_SESSION_ERR; + goto out; + } + + for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { + if (pptr->method == TMPDIR && access(pptr->instance_prefix, F_OK) == 0) { + pid = fork(); + if (pid == 0) { +#ifdef WITH_SELINUX + if (idata->flags & PAMNS_SELINUX_ENABLED) { + if (setexeccon(NULL) < 0) + exit(1); + } +#endif + if (execl("/bin/rm", "/bin/rm", "-rf", pptr->instance_prefix, (char *)NULL) < 0) + exit(1); + } else if (pid > 0) { + while (((rc = waitpid(pid, &status, 0)) == (pid_t)-1) && + (errno == EINTR)); + if (rc == (pid_t)-1) { + pam_syslog(idata->pamh, LOG_ERR, "waitpid failed- %m"); + rc = PAM_SESSION_ERR; + goto out; + } + if (!WIFEXITED(status) || WIFSIGNALED(status) > 0) { + pam_syslog(idata->pamh, LOG_ERR, + "Error removing %s", pptr->instance_prefix); + } + } else if (pid < 0) { + pam_syslog(idata->pamh, LOG_ERR, + "Cannot fork to run namespace init script, %m"); + rc = PAM_SESSION_ERR; + goto out; + } + } + } + + rc = PAM_SUCCESS; +out: + signal(SIGCHLD, osighand); + return rc; +} /* * This function checks to see if polyinstantiation is needed for any @@ -1111,13 +1208,22 @@ * disassociate from the parent namespace. */ if (need_poly) { + if (pam_set_data(idata->pamh, NAMESPACE_POLYDIR_DATA, idata->polydirs_ptr, + cleanup_data) != PAM_SUCCESS) { + pam_syslog(idata->pamh, LOG_ERR, + "Unable to set namespace data"); + return PAM_SYSTEM_ERR; + } if (unshare(CLONE_NEWNS) < 0) { - pam_syslog(idata->pamh, LOG_ERR, + pam_set_data(idata->pamh, NAMESPACE_POLYDIR_DATA, NULL, NULL); + pam_syslog(idata->pamh, LOG_ERR, "Unable to unshare from parent namespace, %m"); return PAM_SESSION_ERR; } - } else + } else { + del_polydir_list(idata->polydirs_ptr); return PAM_SUCCESS; + } /* * Again cycle through all polyinstantiated directories, this time, @@ -1144,7 +1250,8 @@ * umount */ if ((changing_dir = cwd_in(pptr->dir, idata)) < 0) { - return PAM_SESSION_ERR; + retval = PAM_SESSION_ERR; + goto out; } else if (changing_dir) { if (idata->flags & PAMNS_DEBUG) pam_syslog(idata->pamh, LOG_DEBUG, "changing cwd"); @@ -1172,8 +1279,10 @@ int saved_errno = errno; pam_syslog(idata->pamh, LOG_ERR, "Unmount of %s failed, %m", pptr->dir); - if (saved_errno != EINVAL) - return PAM_SESSION_ERR; + if (saved_errno != EINVAL) { + retval = PAM_SESSION_ERR; + goto out; + } } else if (idata->flags & PAMNS_DEBUG) pam_syslog(idata->pamh, LOG_DEBUG, "Umount succeeded %s", pptr->dir); @@ -1185,7 +1294,9 @@ break; } } - +out: + if (retval != PAM_SUCCESS) + cleanup_tmpdirs(idata); return retval; } @@ -1224,8 +1335,10 @@ } else if (idata->flags & PAMNS_DEBUG) pam_syslog(idata->pamh, LOG_DEBUG, "Unmount of %s succeeded", pptr->dir); - } + } } + + cleanup_tmpdirs(idata); return 0; } @@ -1349,7 +1462,8 @@ } else if (idata.flags & PAMNS_DEBUG) pam_syslog(idata.pamh, LOG_DEBUG, "Nothing to polyinstantiate"); - del_polydir_list(idata.polydirs_ptr); + if (retval != PAM_SUCCESS) + del_polydir_list(idata.polydirs_ptr); return retval; } @@ -1364,6 +1478,7 @@ struct instance_data idata; char *user_name; struct passwd *pwd; + const void *polyptr; /* init instance data */ idata.flags = 0; @@ -1425,16 +1540,12 @@ idata.user = user_name; idata.uid = pwd->pw_uid; - /* - * Parse namespace configuration file which lists directories that - * are polyinstantiated, directories where instance directories are - * created and the method used for polyinstantiation. - */ - retval = parse_config_file(&idata); - if ((retval != PAM_SUCCESS) || !idata.polydirs_ptr) { - del_polydir_list(idata.polydirs_ptr); - return PAM_SESSION_ERR; - } + retval = pam_get_data(idata.pamh, NAMESPACE_POLYDIR_DATA, &polyptr); + if (retval != PAM_SUCCESS || polyptr == NULL) + /* nothing to reset */ + return PAM_SUCCESS; + + idata.polydirs_ptr = polyptr; if (idata.flags & PAMNS_DEBUG) pam_syslog(idata.pamh, LOG_DEBUG, "Resetting namespace for pid %d", @@ -1449,7 +1560,9 @@ pam_syslog(idata.pamh, LOG_DEBUG, "resetting namespace ok for pid %d", getpid()); } - del_polydir_list(idata.polydirs_ptr); + + pam_set_data(idata.pamh, NAMESPACE_POLYDIR_DATA, NULL, NULL); + return PAM_SUCCESS; }