diff --git a/0003-Fix-CVE-2024-10963.patch b/0003-Fix-CVE-2024-10963.patch new file mode 100644 index 0000000000000000000000000000000000000000..3455bb28538f460ea4ef847c572457289b60c7f9 --- /dev/null +++ b/0003-Fix-CVE-2024-10963.patch @@ -0,0 +1,221 @@ +diff --git a/modules/pam_access/access.conf.5.xml b/modules/pam_access/access.conf.5.xml +index ff1cb22..fc24411 100644 +--- a/modules/pam_access/access.conf.5.xml ++++ b/modules/pam_access/access.conf.5.xml +@@ -222,6 +222,10 @@ + item and the line will be most probably ignored. For this reason, it is not + recommended to put spaces around the ':' characters. + ++ ++ Hostnames should be written as Fully-Qualified Host Name (FQHN) to avoid ++ confusion with device names or PAM service names. ++ + + + +@@ -246,4 +250,4 @@ + introduced by Mike Becher <mike.becher@lrz-muenchen.de>. + + +- +\ No newline at end of file ++ +diff --git a/modules/pam_access/pam_access.8.xml b/modules/pam_access/pam_access.8.xml +index 010e749..b3edad0 100644 +--- a/modules/pam_access/pam_access.8.xml ++++ b/modules/pam_access/pam_access.8.xml +@@ -22,11 +22,14 @@ + + debug + ++ ++ noaudit ++ + + nodefgroup + + +- noaudit ++ nodns + + + accessfile=file +@@ -129,6 +132,33 @@ + + + ++ ++ ++ nodefgroup ++ ++ ++ ++ User tokens which are not enclosed in parentheses will not be ++ matched against the group database. The backwards compatible default is ++ to try the group database match even for tokens not enclosed ++ in parentheses. ++ ++ ++ ++ ++ ++ ++ nodns ++ ++ ++ ++ Do not try to resolve tokens as hostnames, only IPv4 and IPv6 ++ addresses will be resolved. Which means to allow login from a ++ remote host, the IP addresses need to be specified in access.conf. ++ ++ ++ ++ + + + fieldsep=separators +@@ -170,20 +200,6 @@ + + + +- +- +- nodefgroup +- +- +- +- User tokens which are not enclosed in parentheses will not be +- matched against the group database. The backwards compatible default is +- to try the group database match even for tokens not enclosed +- in parentheses. +- +- +- +- + + + +@@ -286,4 +302,4 @@ + was developed and provided by Mike Becher <mike.becher@lrz-muenchen.de>. + + +- +\ No newline at end of file ++ +diff --git a/modules/pam_access/pam_access.c b/modules/pam_access/pam_access.c +index f70b7e4..d06496c 100644 +--- a/modules/pam_access/pam_access.c ++++ b/modules/pam_access/pam_access.c +@@ -99,6 +99,7 @@ struct login_info { + int debug; /* Print debugging messages. */ + int only_new_group_syntax; /* Only allow group entries of the form "(xyz)" */ + int noaudit; /* Do not audit denials */ ++ int nodns; /* Do not try to resolve tokens as hostnames */ + const char *fs; /* field separator */ + const char *sep; /* list-element separator */ + int from_remote_host; /* If PAM_RHOST was used for from */ +@@ -150,6 +151,8 @@ parse_args(pam_handle_t *pamh, struct login_info *loginfo, + loginfo->only_new_group_syntax = YES; + } else if (strcmp (argv[i], "noaudit") == 0) { + loginfo->noaudit = YES; ++ } else if (strcmp (argv[i], "nodns") == 0) { ++ loginfo->nodns = YES; + } else { + pam_syslog(pamh, LOG_ERR, "unrecognized option [%s]", argv[i]); + } +@@ -732,7 +735,7 @@ remote_match (pam_handle_t *pamh, char *tok, struct login_info *item) + if ((str_len = strlen(string)) > tok_len + && strcasecmp(tok, string + str_len - tok_len) == 0) + return YES; +- } else if (tok[tok_len - 1] == '.') { /* internet network numbers (end with ".") */ ++ } else if (tok[tok_len - 1] == '.') { /* internet network numbers/subnet (end with ".") */ + struct addrinfo hint; + + memset (&hint, '\0', sizeof (hint)); +@@ -807,6 +810,39 @@ string_match (pam_handle_t *pamh, const char *tok, const char *string, + } + + ++static int ++is_device (pam_handle_t *pamh, const char *tok) ++{ ++ struct stat st; ++ const char *dev = "/dev/"; ++ char *devname; ++ ++ devname = malloc (strlen(dev) + strlen (tok) + 1); ++ if (devname == NULL) { ++ pam_syslog(pamh, LOG_ERR, "Cannot allocate memory for device name: %m"); ++ /* ++ * We should return an error and abort, but pam_access has no good ++ * error handling. ++ */ ++ return NO; ++ } ++ ++ char *cp = stpcpy (devname, dev); ++ strcpy (cp, tok); ++ ++ if (lstat(devname, &st) != 0) ++ { ++ free (devname); ++ return NO; ++ } ++ free (devname); ++ ++ if (S_ISCHR(st.st_mode)) ++ return YES; ++ ++ return NO; ++} ++ + /* network_netmask_match - match a string against one token + * where string is a hostname or ip (v4,v6) address and tok + * represents either a hostname, a single ip (v4,v6) address +@@ -868,10 +904,42 @@ network_netmask_match (pam_handle_t *pamh, + return NO; + } + } ++ else if (isipaddr(tok, NULL, NULL) == YES) ++ { ++ if (getaddrinfo (tok, NULL, NULL, &ai) != 0) ++ { ++ if (item->debug) ++ pam_syslog(pamh, LOG_DEBUG, "cannot resolve IP address \"%s\"", tok); ++ ++ return NO; ++ } ++ netmask_ptr = NULL; ++ } ++ else if (item->nodns) ++ { ++ /* Only hostnames are left, which we would need to resolve via DNS */ ++ return NO; ++ } + else + { ++ /* Bail out on X11 Display entries and ttys. */ ++ if (tok[0] == ':') ++ { ++ if (item->debug) ++ pam_syslog (pamh, LOG_DEBUG, ++ "network_netmask_match: tok=%s is X11 display", tok); ++ return NO; ++ } ++ if (is_device (pamh, tok)) ++ { ++ if (item->debug) ++ pam_syslog (pamh, LOG_DEBUG, ++ "network_netmask_match: tok=%s is a TTY", tok); ++ return NO; ++ } ++ + /* +- * It is either an IP address or a hostname. ++ * It is most likely a hostname. + * Let getaddrinfo sort everything out + */ + if (getaddrinfo (tok, NULL, NULL, &ai) != 0) +-- +2.43.5 + diff --git a/0004-FIX-CVE-2024-22365.patch b/0004-FIX-CVE-2024-22365.patch new file mode 100644 index 0000000000000000000000000000000000000000..dfecc927f93507a16dd4d588e741d138a42b448e --- /dev/null +++ b/0004-FIX-CVE-2024-22365.patch @@ -0,0 +1,39 @@ +diff --git a/modules/pam_namespace/pam_namespace.c b/modules/pam_namespace/pam_namespace.c +index f34ce93..ef85644 100644 +--- a/modules/pam_namespace/pam_namespace.c ++++ b/modules/pam_namespace/pam_namespace.c +@@ -1194,7 +1194,7 @@ static int protect_dir(const char *path, mode_t mode, int do_mkdir, + int dfd = AT_FDCWD; + int dfd_next; + int save_errno; +- int flags = O_RDONLY; ++ int flags = O_RDONLY | O_DIRECTORY; + int rv = -1; + struct stat st; + +@@ -1248,22 +1248,6 @@ static int protect_dir(const char *path, mode_t mode, int do_mkdir, + rv = openat(dfd, dir, flags); + } + +- if (rv != -1) { +- if (fstat(rv, &st) != 0) { +- save_errno = errno; +- close(rv); +- rv = -1; +- errno = save_errno; +- goto error; +- } +- if (!S_ISDIR(st.st_mode)) { +- close(rv); +- errno = ENOTDIR; +- rv = -1; +- goto error; +- } +- } +- + if (flags & O_NOFOLLOW) { + /* we are inside user-owned dir - protect */ + if (protect_mount(rv, p, idata) == -1) { +-- +2.43.5 + diff --git a/0006-FIX-CVE-2025-6020-1.patch b/0006-FIX-CVE-2025-6020-1.patch new file mode 100644 index 0000000000000000000000000000000000000000..42d12935c99d57e368d124bfa580f81a75ae76a5 --- /dev/null +++ b/0006-FIX-CVE-2025-6020-1.patch @@ -0,0 +1,1128 @@ +From df1dab1a1a7900650ad4be157fea1a002048cc49 Mon Sep 17 00:00:00 2001 +From: Olivier Bal-Petre +Date: Tue, 4 Mar 2025 14:37:02 +0100 +Subject: [PATCH 1/3] pam_namespace: fix potential privilege escalation + +Existing protection provided by protect_dir() and protect_mount() were +bind mounting on themselves all directories part of the to-be-secured +paths. However, this works *only* against attacks executed by processes +in the same mount namespace as the one the mountpoint was created in. +Therefore, a user with an out-of-mount-namespace access, or multiple +users colluding, could exploit multiple race conditions, and, for +instance, elevate their privileges to root. + +This commit keeps the existing protection as a defense in depth +measure, and to keep the existing behavior of the module. However, +it converts all the needed function calls to operate on file +descriptors instead of absolute paths to protect against race +conditions globally. + +Signed-off-by: Olivier Bal-Petre +Signed-off-by: Dmitry V. Levin + +Conflict:NA +Reference:https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/pam/1.5.3-5ubuntu5.4/pam_1.5.3-5ubuntu5.4.debian.tar.xz + +--- + modules/pam_namespace/pam_namespace.c | 637 ++++++++++++++++++-------- + modules/pam_namespace/pam_namespace.h | 11 + + 2 files changed, 458 insertions(+), 190 deletions(-) + +--- a/modules/pam_namespace/pam_namespace.c ++++ b/modules/pam_namespace/pam_namespace.c +@@ -78,6 +78,8 @@ pam_snprintf(char *str, size_t size, con + ##__VA_ARGS__) + + ++#define MAGIC_LNK_FD_SIZE 64 ++ + /* --- evaluating all files in VENDORDIR/security/namespace.d and /etc/security/namespace.d --- */ + static const char *base_name(const char *path) + { +@@ -104,7 +106,7 @@ strip_trailing_slashes(char *str) + static int protect_mount(int dfd, const char *path, struct instance_data *idata) + { + struct protect_dir_s *dir = idata->protect_dirs; +- char tmpbuf[64]; ++ char tmpbuf[MAGIC_LNK_FD_SIZE]; + + while (dir != NULL) { + if (strcmp(path, dir->dir) == 0) { +@@ -149,56 +151,107 @@ static int protect_mount(int dfd, const + return 0; + } + +-static int protect_dir(const char *path, mode_t mode, int do_mkdir, ++/* ++ * Returns a fd to the given absolute path, acquired securely. This means: ++ * - iterating on each segment of the path, ++ * - not following user symlinks, ++ * - using race-free operations. ++ * ++ * Takes a bit mask to specify the operation mode: ++ * - SECURE_OPENDIR_PROTECT: call protect_mount() on each unsafe segment of path ++ * - SECURE_OPENDIR_MKDIR: create last segment of path if does not exist ++ * - SECURE_OPENDIR_FULL_FD: open the directory with O_RDONLY instead of O_PATH, ++ * allowing more operations to be done with the returned fd ++ * ++ * Be aware that using SECURE_OPENDIR_PROTECT: ++ * - will modify some external state (global structure...) and should not be ++ * called in cleanup code paths. See wrapper secure_opendir_stateless() ++ * - need a non-NULL idata to call protect_mount() ++ */ ++static int secure_opendir(const char *path, int opm, mode_t mode, + struct instance_data *idata) + { +- char *p = strdup(path); ++ char *p; + char *d; +- char *dir = p; +- int dfd = AT_FDCWD; ++ char *dir; ++ int dfd = -1; + int dfd_next; + int save_errno; +- int flags = O_RDONLY | O_DIRECTORY; ++ int flags = O_DIRECTORY | O_CLOEXEC; + int rv = -1; + struct stat st; + +- if (p == NULL) { ++ if (opm & SECURE_OPENDIR_FULL_FD) ++ flags |= O_RDONLY; ++ else ++ flags |= O_PATH; ++ ++ /* Check for args consistency */ ++ if ((opm & SECURE_OPENDIR_PROTECT) && idata == NULL) + return -1; +- } + +- if (*dir == '/') { +- dfd = open("/", flags); +- if (dfd == -1) { +- goto error; +- } +- dir++; /* assume / is safe */ ++ /* Accept only absolute paths */ ++ if (*path != '/') ++ return -1; ++ ++ dir = p = strdup(path); ++ if (p == NULL) ++ return -1; ++ ++ /* Assume '/' is safe */ ++ dfd = open("/", flags); ++ if (dfd == -1) ++ goto error; ++ ++ /* Needed to not loop too far and call openat() on NULL */ ++ strip_trailing_slashes(p); ++ ++ dir++; ++ ++ /* In case path is '/' */ ++ if (*dir == '\0') { ++ free(p); ++ return dfd; + } + + while ((d=strchr(dir, '/')) != NULL) { + *d = '\0'; ++ + dfd_next = openat(dfd, dir, flags); +- if (dfd_next == -1) { ++ if (dfd_next == -1) + goto error; +- } +- +- if (dfd != AT_FDCWD) +- close(dfd); +- dfd = dfd_next; + +- if (fstat(dfd, &st) != 0) { ++ if (fstat(dfd_next, &st) != 0) { ++ close(dfd_next); + goto error; + } + +- if (flags & O_NOFOLLOW) { ++ if ((flags & O_NOFOLLOW) && (opm & SECURE_OPENDIR_PROTECT)) { + /* we are inside user-owned dir - protect */ +- if (protect_mount(dfd, p, idata) == -1) ++ if (protect_mount(dfd_next, p, idata) == -1) { ++ close(dfd_next); ++ goto error; ++ } ++ /* ++ * Reopen the directory to obtain a new descriptor ++ * after protect_mount(), this is necessary in cases ++ * when another directory is going to be mounted over ++ * the given path. ++ */ ++ close(dfd_next); ++ dfd_next = openat(dfd, dir, flags); ++ if (dfd_next == -1) + goto error; +- } else if (st.st_uid != 0 || st.st_gid != 0 || +- (st.st_mode & S_IWOTH)) { ++ } else if (st.st_uid != 0 ++ || (st.st_gid != 0 && (st.st_mode & S_IWGRP)) ++ || (st.st_mode & S_IWOTH)) { + /* do not follow symlinks on subdirectories */ + flags |= O_NOFOLLOW; + } + ++ close(dfd); ++ dfd = dfd_next; ++ + *d = '/'; + dir = d + 1; + } +@@ -206,13 +259,14 @@ static int protect_dir(const char *path, + rv = openat(dfd, dir, flags); + + if (rv == -1) { +- if (!do_mkdir || mkdirat(dfd, dir, mode) != 0) { ++ if ((opm & SECURE_OPENDIR_MKDIR) && mkdirat(dfd, dir, mode) == 0) ++ rv = openat(dfd, dir, flags); ++ ++ if (rv == -1) + goto error; +- } +- rv = openat(dfd, dir, flags); + } + +- if (flags & O_NOFOLLOW) { ++ if ((flags & O_NOFOLLOW) && (opm & SECURE_OPENDIR_PROTECT)) { + /* we are inside user-owned dir - protect */ + if (protect_mount(rv, p, idata) == -1) { + save_errno = errno; +@@ -220,18 +274,95 @@ static int protect_dir(const char *path, + rv = -1; + errno = save_errno; + } ++ /* ++ * Reopen the directory to obtain a new descriptor after ++ * protect_mount(), this is necessary in cases when another ++ * directory is going to be mounted over the given path. ++ */ ++ close(rv); ++ rv = openat(dfd, dir, flags); + } + + error: + save_errno = errno; + free(p); +- if (dfd != AT_FDCWD && dfd >= 0) ++ if (dfd >= 0) + close(dfd); + errno = save_errno; + + return rv; + } + ++/* ++ * Returns a fd to the given path, acquired securely. ++ * It can be called in all situations, including in cleanup code paths, as ++ * it does not modify external state (no access to global structures...). ++ */ ++static int secure_opendir_stateless(const char *path) ++{ ++ return secure_opendir(path, 0, 0, NULL); ++} ++ ++/* ++ * Umount securely the given path, even if the directories along ++ * the path are under user control. It should protect against ++ * symlinks attacks and race conditions. ++ */ ++static int secure_umount(const char *path) ++{ ++ int save_errno; ++ int rv = -1; ++ int dfd = -1; ++ char s_path[MAGIC_LNK_FD_SIZE]; ++ ++ dfd = secure_opendir_stateless(path); ++ if (dfd == -1) ++ return rv; ++ ++ if (pam_sprintf(s_path, "/proc/self/fd/%d", dfd) < 0) ++ goto error; ++ ++ /* ++ * We still have a fd open to path itself, ++ * so we need to do a lazy umount. ++ */ ++ rv = umount2(s_path, MNT_DETACH); ++ ++error: ++ save_errno = errno; ++ close(dfd); ++ errno = save_errno; ++ return rv; ++} ++ ++/* ++ * Rmdir the given path securely, protecting against symlinks attacks ++ * and race conditions. ++ * This function is currently called only in cleanup code paths where ++ * any errors returned are not handled, so do not handle them either. ++ * Basically, try to rmdir the path on a best-effort basis. ++ */ ++static void secure_try_rmdir(const char *path) ++{ ++ int dfd; ++ char *buf; ++ char *parent; ++ ++ buf = strdup(path); ++ if (buf == NULL) ++ return; ++ ++ parent = dirname(buf); ++ ++ dfd = secure_opendir_stateless(parent); ++ if (dfd >= 0) { ++ unlinkat(dfd, base_name(path), AT_REMOVEDIR); ++ close(dfd); ++ } ++ ++ free(buf); ++} ++ + /* Evaluating a list of files which have to be parsed in the right order: + * + * - If etc/security/namespace.d/@filename@.conf exists, then +@@ -357,7 +488,7 @@ static void unprotect_dirs(struct protec + struct protect_dir_s *next; + + while (dir != NULL) { +- umount(dir->dir); ++ secure_umount(dir->dir); + free(dir->dir); + next = dir->next; + free(dir); +@@ -761,13 +892,9 @@ static int process_line(char *line, cons + goto skipping; + } + +-#define COPY_STR(dst, src, apd) \ +- pam_sprintf((dst), "%s%s", (src), (apd)) +- +- if (COPY_STR(poly->dir, dir, "") < 0 +- || COPY_STR(poly->rdir, rdir, "") < 0 +- || COPY_STR(poly->instance_prefix, instance_prefix, +- poly->method == TMPDIR ? "XXXXXX" : "") < 0) { ++ if (pam_sprintf(poly->dir, "%s", dir) < 0 ++ || pam_sprintf(poly->rdir, "%s", rdir) < 0 ++ || pam_sprintf(poly->instance_prefix, "%s", instance_prefix) < 0) { + pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames too long"); + goto skipping; + } +@@ -1050,6 +1177,23 @@ static char *md5hash(const char *instnam + } + + #ifdef WITH_SELINUX ++static char *secure_getfilecon(pam_handle_t *pamh, const char *dir) ++{ ++ char *ctx = NULL; ++ int dfd = secure_opendir(dir, SECURE_OPENDIR_FULL_FD, 0, NULL); ++ if (dfd < 0) { ++ pam_syslog(pamh, LOG_ERR, "Error getting fd to %s: %m", dir); ++ return NULL; ++ } ++ if (fgetfilecon(dfd, &ctx) < 0) ++ ctx = NULL; ++ if (ctx == NULL) ++ pam_syslog(pamh, LOG_ERR, ++ "Error getting poly dir context for %s: %m", dir); ++ close(dfd); ++ return ctx; ++} ++ + static int form_context(const struct polydir_s *polyptr, + char **i_context, char **origcon, + struct instance_data *idata) +@@ -1061,12 +1205,9 @@ static int form_context(const struct pol + /* + * Get the security context of the directory to polyinstantiate. + */ +- rc = getfilecon(polyptr->dir, origcon); +- if (rc < 0 || *origcon == NULL) { +- pam_syslog(idata->pamh, LOG_ERR, +- "Error getting poly dir context, %m"); ++ *origcon = secure_getfilecon(idata->pamh, polyptr->dir); ++ if (*origcon == NULL) + return PAM_SESSION_ERR; +- } + + if (polyptr->method == USER) return PAM_SUCCESS; + +@@ -1163,29 +1304,52 @@ static int form_context(const struct pol + #endif + + /* +- * poly_name returns the name of the polyinstantiated instance directory ++ * From the instance differentiation string, set in the polyptr structure: ++ * - the absolute path to the instance dir, ++ * - the absolute path to the previous dir (parent), ++ * - the instance name (may be different than the instance differentiation string) ++ */ ++static int set_polydir_paths(struct polydir_s *polyptr, const char *inst_differentiation) ++{ ++ char *tmp; ++ ++ if (pam_sprintf(polyptr->instance_absolute, "%s%s", ++ polyptr->instance_prefix, inst_differentiation) < 0) ++ return -1; ++ ++ polyptr->instname = strrchr(polyptr->instance_absolute, '/') + 1; ++ ++ if (pam_sprintf(polyptr->instance_parent, "%s", polyptr->instance_absolute) < 0) ++ return -1; ++ ++ tmp = strrchr(polyptr->instance_parent, '/') + 1; ++ *tmp = '\0'; ++ ++ return 0; ++} ++ ++/* ++ * Set the name of the polyinstantiated instance directory + * based on the method used for polyinstantiation (user, context or level) + * In addition, the function also returns the security contexts of the + * original directory to polyinstantiate and the polyinstantiated instance + * directory. + */ + #ifdef WITH_SELINUX +-static int poly_name(const struct polydir_s *polyptr, char **i_name, +- char **i_context, char **origcon, +- struct instance_data *idata) ++static int poly_name(struct polydir_s *polyptr, char **i_context, ++ char **origcon, struct instance_data *idata) + #else +-static int poly_name(const struct polydir_s *polyptr, char **i_name, +- struct instance_data *idata) ++static int poly_name(struct polydir_s *polyptr, struct instance_data *idata) + #endif + { + int rc; ++ char *inst_differentiation = NULL; + char *hash = NULL; + enum polymethod pm; + #ifdef WITH_SELINUX + char *rawcon = NULL; + #endif + +- *i_name = NULL; + #ifdef WITH_SELINUX + *i_context = NULL; + *origcon = NULL; +@@ -1219,7 +1383,7 @@ static int poly_name(const struct polydi + + switch (pm) { + case USER: +- if ((*i_name = strdup(idata->user)) == NULL) ++ if ((inst_differentiation = strdup(idata->user)) == NULL) + goto fail; + break; + +@@ -1231,20 +1395,24 @@ static int poly_name(const struct polydi + goto fail; + } + if (polyptr->flags & POLYDIR_SHARED) +- *i_name = strdup(rawcon); ++ inst_differentiation = strdup(rawcon); + else +- *i_name = pam_asprintf("%s_%s", rawcon, idata->user); +- if (*i_name == NULL) ++ inst_differentiation = pam_asprintf("%s_%s", rawcon, idata->user); ++ if (inst_differentiation == NULL) + goto fail; + break; + + #endif /* WITH_SELINUX */ + + case TMPDIR: ++ if ((inst_differentiation = strdup("XXXXXX")) == NULL) ++ goto fail; ++ goto success; ++ + case TMPFS: +- if ((*i_name=strdup("")) == NULL) ++ if ((inst_differentiation=strdup("")) == NULL) + goto fail; +- return PAM_SUCCESS; ++ goto success; + + default: + if (idata->flags & PAMNS_DEBUG) +@@ -1253,32 +1421,37 @@ static int poly_name(const struct polydi + } + + if (idata->flags & PAMNS_DEBUG) +- pam_syslog(idata->pamh, LOG_DEBUG, "poly_name %s", *i_name); ++ pam_syslog(idata->pamh, LOG_DEBUG, "poly_name %s", inst_differentiation); + +- if ((idata->flags & PAMNS_GEN_HASH) || strlen(*i_name) > NAMESPACE_MAX_DIR_LEN) { +- hash = md5hash(*i_name, idata); ++ if ((idata->flags & PAMNS_GEN_HASH) || strlen(inst_differentiation) > NAMESPACE_MAX_DIR_LEN) { ++ hash = md5hash(inst_differentiation, idata); + if (hash == NULL) { + goto fail; + } + if (idata->flags & PAMNS_GEN_HASH) { +- free(*i_name); +- *i_name = hash; ++ free(inst_differentiation); ++ inst_differentiation = hash; + hash = NULL; + } else { + char *newname = + pam_asprintf("%.*s_%s", + NAMESPACE_MAX_DIR_LEN - 1 - (int)strlen(hash), +- *i_name, hash); ++ inst_differentiation, hash); + if (newname == NULL) + goto fail; +- free(*i_name); +- *i_name = newname; ++ free(inst_differentiation); ++ inst_differentiation = newname; + } + } +- rc = PAM_SUCCESS; + ++success: ++ if (set_polydir_paths(polyptr, inst_differentiation) == -1) ++ goto fail; ++ ++ rc = PAM_SUCCESS; + fail: + free(hash); ++ free(inst_differentiation); + #ifdef WITH_SELINUX + freecon(rawcon); + #endif +@@ -1289,55 +1462,35 @@ fail: + freecon(*origcon); + *origcon = NULL; + #endif +- free(*i_name); +- *i_name = NULL; + } + return rc; + } + +-static int check_inst_parent(char *ipath, struct instance_data *idata) ++static int check_inst_parent(int dfd, struct instance_data *idata) + { + struct stat instpbuf; +- char *inst_parent, *trailing_slash; +- int dfd; ++ + /* +- * stat the instance parent path to make sure it exists +- * and is a directory. Check that its mode is 000 (unless the +- * admin explicitly instructs to ignore the instance parent +- * mode by the "ignore_instance_parent_mode" argument). ++ * Stat the instance parent directory to make sure it's writable by ++ * root only (unless the admin explicitly instructs to ignore the ++ * instance parent mode by the "ignore_instance_parent_mode" argument). + */ +- inst_parent = strdup(ipath); +- if (!inst_parent) { +- pam_syslog(idata->pamh, LOG_CRIT, "Error allocating pathname string"); +- return PAM_SESSION_ERR; +- } + +- trailing_slash = strrchr(inst_parent, '/'); +- if (trailing_slash) +- *trailing_slash = '\0'; +- +- dfd = protect_dir(inst_parent, 0, 1, idata); ++ if (idata->flags & PAMNS_IGN_INST_PARENT_MODE) ++ return PAM_SUCCESS; + +- if (dfd == -1 || fstat(dfd, &instpbuf) < 0) { ++ if (fstat(dfd, &instpbuf) < 0) { + pam_syslog(idata->pamh, LOG_ERR, +- "Error creating or accessing instance parent %s, %m", inst_parent); +- if (dfd != -1) +- close(dfd); +- free(inst_parent); ++ "Error accessing instance parent, %m"); + return PAM_SESSION_ERR; + } + +- if ((idata->flags & PAMNS_IGN_INST_PARENT_MODE) == 0) { +- if ((instpbuf.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) || instpbuf.st_uid != 0) { +- pam_syslog(idata->pamh, LOG_ERR, "Mode of inst parent %s not 000 or owner not root", +- inst_parent); +- close(dfd); +- free(inst_parent); +- return PAM_SESSION_ERR; +- } ++ if ((instpbuf.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) || instpbuf.st_uid != 0) { ++ pam_syslog(idata->pamh, LOG_ERR, ++ "Mode of inst parent not 000 or owner not root"); ++ return PAM_SESSION_ERR; + } +- close(dfd); +- free(inst_parent); ++ + return PAM_SUCCESS; + } + +@@ -1475,14 +1628,16 @@ static int create_polydir(struct polydir + } + #endif + +- rc = protect_dir(dir, mode, 1, idata); ++ rc = secure_opendir(dir, ++ SECURE_OPENDIR_PROTECT | SECURE_OPENDIR_MKDIR | SECURE_OPENDIR_FULL_FD, ++ mode, idata); + if (rc == -1) { + pam_syslog(idata->pamh, LOG_ERR, + "Error creating directory %s: %m", dir); + #ifdef WITH_SELINUX + freecon(oldcon_raw); + #endif +- return PAM_SESSION_ERR; ++ return -1; + } + + #ifdef WITH_SELINUX +@@ -1503,9 +1658,9 @@ static int create_polydir(struct polydir + pam_syslog(idata->pamh, LOG_ERR, + "Error changing mode of directory %s: %m", dir); + close(rc); +- umount(dir); /* undo the eventual protection bind mount */ +- rmdir(dir); +- return PAM_SESSION_ERR; ++ secure_umount(dir); /* undo the eventual protection bind mount */ ++ secure_try_rmdir(dir); ++ return -1; + } + } + +@@ -1523,42 +1678,38 @@ static int create_polydir(struct polydir + pam_syslog(idata->pamh, LOG_ERR, + "Unable to change owner on directory %s: %m", dir); + close(rc); +- umount(dir); /* undo the eventual protection bind mount */ +- rmdir(dir); +- return PAM_SESSION_ERR; ++ secure_umount(dir); /* undo the eventual protection bind mount */ ++ secure_try_rmdir(dir); ++ return -1; + } + +- close(rc); +- + if (idata->flags & PAMNS_DEBUG) + pam_syslog(idata->pamh, LOG_DEBUG, + "Polydir owner %u group %u", uid, gid); + +- return PAM_SUCCESS; ++ return rc; + } + + /* +- * Create polyinstantiated instance directory (ipath). ++ * Create polyinstantiated instance directory. ++ * To protect against races, changes are done on a fd to the parent of the ++ * instance directory (dfd_iparent) and a relative path (polyptr->instname). ++ * The absolute path (polyptr->instance_absolute) is only updated when creating ++ * a tmpdir and used for logging purposes. + */ + #ifdef WITH_SELINUX +-static int create_instance(struct polydir_s *polyptr, char *ipath, struct stat *statbuf, +- const char *icontext, const char *ocontext, +- struct instance_data *idata) ++static int create_instance(struct polydir_s *polyptr, int dfd_iparent, ++ struct stat *statbuf, const char *icontext, const char *ocontext, ++ struct instance_data *idata) + #else +-static int create_instance(struct polydir_s *polyptr, char *ipath, struct stat *statbuf, +- struct instance_data *idata) ++static int create_instance(struct polydir_s *polyptr, int dfd_iparent, ++ struct stat *statbuf, struct instance_data *idata) + #endif + { + struct stat newstatbuf; + int fd; + + /* +- * Check to make sure instance parent is valid. +- */ +- if (check_inst_parent(ipath, idata)) +- return PAM_SESSION_ERR; +- +- /* + * Create instance directory and set its security context to the context + * returned by the security policy. Set its mode and ownership + * attributes to match that of the original directory that is being +@@ -1566,29 +1717,39 @@ static int create_instance(struct polydi + */ + + 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) { ++ char s_path[PATH_MAX]; ++ /* ++ * Create the template for mkdtemp() as a magic link based on ++ * our existing fd to avoid symlink attacks and races. ++ */ ++ if (pam_sprintf(s_path, "/proc/self/fd/%d/%s", dfd_iparent, polyptr->instname) < 0 ++ || mkdtemp(s_path) == NULL) { ++ pam_syslog(idata->pamh, LOG_ERR, ++ "Error creating temporary instance dir %s, %m", ++ polyptr->instance_absolute); ++ polyptr->method = NONE; /* do not clean up! */ ++ return PAM_SESSION_ERR; ++ } ++ ++ /* Copy the actual directory name to polyptr->instname */ ++ strcpy(polyptr->instname, base_name(s_path)); ++ } else if (mkdirat(dfd_iparent, polyptr->instname, S_IRUSR) < 0) { + if (errno == EEXIST) + return PAM_IGNORE; + else { + pam_syslog(idata->pamh, LOG_ERR, "Error creating %s, %m", +- ipath); ++ polyptr->instance_absolute); + return PAM_SESSION_ERR; + } + } + +- /* Open a descriptor to it to prevent races */ +- fd = open(ipath, O_DIRECTORY | O_RDONLY); ++ /* Open a descriptor to prevent races, based on our existing fd. */ ++ fd = openat(dfd_iparent, polyptr->instname, ++ O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC); + if (fd < 0) { +- pam_syslog(idata->pamh, LOG_ERR, "Error opening %s, %m", ipath); +- rmdir(ipath); ++ pam_syslog(idata->pamh, LOG_ERR, "Error opening %s, %m", ++ polyptr->instance_absolute); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + #ifdef WITH_SELINUX +@@ -1598,17 +1759,19 @@ static int create_instance(struct polydi + if (icontext) { + if (fsetfilecon(fd, icontext) < 0) { + pam_syslog(idata->pamh, LOG_ERR, +- "Error setting context of %s to %s", ipath, icontext); ++ "Error setting context of %s to %s", ++ polyptr->instance_absolute, icontext); + close(fd); +- rmdir(ipath); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + } else { + if (fsetfilecon(fd, ocontext) < 0) { + pam_syslog(idata->pamh, LOG_ERR, +- "Error setting context of %s to %s", ipath, ocontext); ++ "Error setting context of %s to %s", ++ polyptr->instance_absolute, ocontext); + close(fd); +- rmdir(ipath); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + } +@@ -1616,9 +1779,9 @@ static int create_instance(struct polydi + #endif + if (fstat(fd, &newstatbuf) < 0) { + pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m", +- ipath); ++ polyptr->instance_absolute); + close(fd); +- rmdir(ipath); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + if (newstatbuf.st_uid != statbuf->st_uid || +@@ -1626,17 +1789,17 @@ static int create_instance(struct polydi + if (fchown(fd, statbuf->st_uid, statbuf->st_gid) < 0) { + pam_syslog(idata->pamh, LOG_ERR, + "Error changing owner for %s, %m", +- ipath); ++ polyptr->instance_absolute); + close(fd); +- rmdir(ipath); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + } + if (fchmod(fd, statbuf->st_mode & 07777) < 0) { + pam_syslog(idata->pamh, LOG_ERR, "Error changing mode for %s, %m", +- ipath); ++ polyptr->instance_absolute); + close(fd); +- rmdir(ipath); ++ unlinkat(dfd_iparent, polyptr->instname, AT_REMOVEDIR); + return PAM_SESSION_ERR; + } + close(fd); +@@ -1655,9 +1818,12 @@ static int ns_setup(struct polydir_s *po + struct instance_data *idata) + { + int retval; ++ int dfd_iparent = -1; ++ int dfd_ipath = -1; ++ int dfd_pptrdir = -1; + int newdir = 1; +- char *inst_dir = NULL; +- char *instname = NULL; ++ char s_ipath[MAGIC_LNK_FD_SIZE]; ++ char s_pptrdir[MAGIC_LNK_FD_SIZE]; + struct stat statbuf; + #ifdef WITH_SELINUX + char *instcontext = NULL, *origcontext = NULL; +@@ -1667,37 +1833,48 @@ static int ns_setup(struct polydir_s *po + pam_syslog(idata->pamh, LOG_DEBUG, + "Set namespace for directory %s", polyptr->dir); + +- retval = protect_dir(polyptr->dir, 0, 0, idata); ++ dfd_pptrdir = secure_opendir(polyptr->dir, SECURE_OPENDIR_PROTECT, 0, idata); + +- if (retval < 0) { ++ if (dfd_pptrdir < 0) { + if (errno != ENOENT || !(polyptr->flags & POLYDIR_CREATE)) { + pam_syslog(idata->pamh, LOG_ERR, "Polydir %s access error: %m", + polyptr->dir); + return PAM_SESSION_ERR; + } +- if (create_polydir(polyptr, idata) != PAM_SUCCESS) ++ dfd_pptrdir = create_polydir(polyptr, idata); ++ if (dfd_pptrdir < 0) + return PAM_SESSION_ERR; +- } else { +- close(retval); + } + + if (polyptr->method == TMPFS) { +- if (mount("tmpfs", polyptr->dir, "tmpfs", polyptr->mount_flags, polyptr->mount_opts) < 0) { +- pam_syslog(idata->pamh, LOG_ERR, "Error mounting tmpfs on %s, %m", +- polyptr->dir); +- return PAM_SESSION_ERR; +- } ++ /* ++ * There is no function mount() that operate on a fd, so instead, we ++ * get the magic link corresponding to the fd and give it to mount(). ++ * This protects against potential races exploitable by an unpriv user. ++ */ ++ if (pam_sprintf(s_pptrdir, "/proc/self/fd/%d", dfd_pptrdir) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error pam_sprintf s_pptrdir"); ++ goto error_out; ++ } + +- if (polyptr->flags & POLYDIR_NOINIT) +- return PAM_SUCCESS; ++ if (mount("tmpfs", s_pptrdir, "tmpfs", polyptr->mount_flags, polyptr->mount_opts) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error mounting tmpfs on %s, %m", ++ polyptr->dir); ++ goto error_out; ++ } + +- return inst_init(polyptr, "tmpfs", idata, 1); ++ if (polyptr->flags & POLYDIR_NOINIT) { ++ retval = PAM_SUCCESS; ++ goto cleanup; ++ } ++ ++ retval = inst_init(polyptr, "tmpfs", idata, 1); ++ goto cleanup; + } + +- if (stat(polyptr->dir, &statbuf) < 0) { +- pam_syslog(idata->pamh, LOG_ERR, "Error stating %s: %m", +- polyptr->dir); +- return PAM_SESSION_ERR; ++ if (fstat(dfd_pptrdir, &statbuf) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error stating %s: %m", polyptr->dir); ++ goto error_out; + } + + /* +@@ -1706,15 +1883,16 @@ static int ns_setup(struct polydir_s *po + * security policy. + */ + #ifdef WITH_SELINUX +- retval = poly_name(polyptr, &instname, &instcontext, +- &origcontext, idata); ++ retval = poly_name(polyptr, &instcontext, &origcontext, idata); + #else +- retval = poly_name(polyptr, &instname, idata); ++ retval = poly_name(polyptr, idata); + #endif + + if (retval != PAM_SUCCESS) { +- if (retval != PAM_IGNORE) ++ if (retval != PAM_IGNORE) { + pam_syslog(idata->pamh, LOG_ERR, "Error getting instance name"); ++ goto error_out; ++ } + goto cleanup; + } else { + #ifdef WITH_SELINUX +@@ -1725,22 +1903,33 @@ static int ns_setup(struct polydir_s *po + #endif + } + +- if ((inst_dir = pam_asprintf("%s%s", polyptr->instance_prefix, instname)) == NULL) +- goto error_out; +- +- if (idata->flags & PAMNS_DEBUG) +- pam_syslog(idata->pamh, LOG_DEBUG, "instance_dir %s", +- inst_dir); ++ /* ++ * Gets a fd in a secure manner (we may be operating on a path under ++ * user control), and check it's compliant. ++ * Then, we should *always* operate on *this* fd and a relative path ++ * to be protected against race conditions. ++ */ ++ dfd_iparent = secure_opendir(polyptr->instance_parent, ++ SECURE_OPENDIR_PROTECT | SECURE_OPENDIR_MKDIR, 0, idata); ++ if (dfd_iparent == -1) { ++ pam_syslog(idata->pamh, LOG_ERR, ++ "polyptr->instance_parent %s access error", ++ polyptr->instance_parent); ++ goto error_out; ++ } ++ if (check_inst_parent(dfd_iparent, idata)) { ++ goto error_out; ++ } + + /* + * Create instance directory with appropriate security + * contexts, owner, group and mode bits. + */ + #ifdef WITH_SELINUX +- retval = create_instance(polyptr, inst_dir, &statbuf, instcontext, +- origcontext, idata); ++ retval = create_instance(polyptr, dfd_iparent, &statbuf, instcontext, ++ origcontext, idata); + #else +- retval = create_instance(polyptr, inst_dir, &statbuf, idata); ++ retval = create_instance(polyptr, dfd_iparent, &statbuf, idata); + #endif + + if (retval == PAM_IGNORE) { +@@ -1753,18 +1942,47 @@ static int ns_setup(struct polydir_s *po + } + + /* ++ * Instead of getting a new secure fd, we reuse the fd opened on directory ++ * polyptr->instance_parent to ensure we are working on the same dir as ++ * previously, and thus ensure that previous checks (e.g. check_inst_parent()) ++ * are still relevant. ++ */ ++ dfd_ipath = openat(dfd_iparent, polyptr->instname, ++ O_PATH | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC); ++ if (dfd_ipath == -1) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error openat on %s, %m", ++ polyptr->instname); ++ goto error_out; ++ } ++ ++ if (pam_sprintf(s_ipath, "/proc/self/fd/%d", dfd_ipath) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error pam_sprintf s_ipath"); ++ goto error_out; ++ } ++ ++ if (pam_sprintf(s_pptrdir, "/proc/self/fd/%d", dfd_pptrdir) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, "Error pam_sprintf s_pptrdir"); ++ goto error_out; ++ } ++ ++ /* + * Bind mount instance directory on top of the polyinstantiated + * directory to provide an instance of polyinstantiated directory + * based on polyinstantiated method. ++ * ++ * Operates on magic links created from two fd obtained securely ++ * to protect against race conditions and symlink attacks. Indeed, ++ * the source and destination can be in a user controled path. + */ +- if (mount(inst_dir, polyptr->dir, NULL, MS_BIND, NULL) < 0) { +- pam_syslog(idata->pamh, LOG_ERR, "Error mounting %s on %s, %m", +- inst_dir, polyptr->dir); ++ if(mount(s_ipath, s_pptrdir, NULL, MS_BIND, NULL) < 0) { ++ pam_syslog(idata->pamh, LOG_ERR, ++ "Error mounting %s on %s (%s on %s), %m", ++ s_ipath, s_pptrdir, polyptr->instance_absolute, polyptr->dir); + goto error_out; + } + + if (!(polyptr->flags & POLYDIR_NOINIT)) +- retval = inst_init(polyptr, inst_dir, idata, newdir); ++ retval = inst_init(polyptr, polyptr->instance_absolute, idata, newdir); + + goto cleanup; + +@@ -1776,8 +1994,12 @@ error_out: + retval = PAM_SESSION_ERR; + + cleanup: +- free(inst_dir); +- free(instname); ++ if (dfd_iparent != -1) ++ close(dfd_iparent); ++ if (dfd_ipath != -1) ++ close(dfd_ipath); ++ if (dfd_pptrdir != -1) ++ close(dfd_pptrdir); + #ifdef WITH_SELINUX + freecon(instcontext); + freecon(origcontext); +@@ -1816,6 +2038,7 @@ static int cleanup_tmpdirs(struct instan + { + struct polydir_s *pptr; + pid_t rc, pid; ++ int dfd = -1; + struct sigaction newsa, oldsa; + int status; + +@@ -1827,7 +2050,17 @@ static int cleanup_tmpdirs(struct instan + } + + for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { +- if (pptr->method == TMPDIR && access(pptr->instance_prefix, F_OK) == 0) { ++ if (pptr->method == TMPDIR) { ++ ++ dfd = secure_opendir_stateless(pptr->instance_parent); ++ if (dfd == -1) ++ continue; ++ ++ if (faccessat(dfd, pptr->instname, F_OK, AT_SYMLINK_NOFOLLOW) != 0) { ++ close(dfd); ++ continue; ++ } ++ + pid = fork(); + if (pid == 0) { + static char *envp[] = { NULL }; +@@ -1837,9 +2070,20 @@ static int cleanup_tmpdirs(struct instan + _exit(1); + } + #endif +- execle("/bin/rm", "/bin/rm", "-rf", pptr->instance_prefix, NULL, envp); ++ if (fchdir(dfd) == -1) { ++ pam_syslog(idata->pamh, LOG_ERR, "Failed fchdir to %s: %m", ++ pptr->instance_absolute); ++ _exit(1); ++ } ++ ++ ++ execle("/bin/rm", "/bin/rm", "-rf", pptr->instname, NULL, envp); + _exit(1); + } else if (pid > 0) { ++ ++ if (dfd != -1) ++ close(dfd); ++ + while (((rc = waitpid(pid, &status, 0)) == (pid_t)-1) && + (errno == EINTR)); + if (rc == (pid_t)-1) { +@@ -1852,6 +2096,10 @@ static int cleanup_tmpdirs(struct instan + "Error removing %s", pptr->instance_prefix); + } + } else if (pid < 0) { ++ ++ if (dfd != -1) ++ close(dfd); ++ + pam_syslog(idata->pamh, LOG_ERR, + "Cannot fork to cleanup temporary directory, %m"); + rc = PAM_SESSION_ERR; +@@ -1875,6 +2123,7 @@ out: + static int setup_namespace(struct instance_data *idata, enum unmnt_op unmnt) + { + int retval = 0, need_poly = 0, changing_dir = 0; ++ int dfd = -1; + char *cptr, *fptr, poly_parent[PATH_MAX]; + struct polydir_s *pptr; + +@@ -1990,13 +2239,21 @@ static int setup_namespace(struct instan + strcpy(poly_parent, "/"); + else if (cptr) + *cptr = '\0'; +- if (chdir(poly_parent) < 0) { ++ ++ dfd = secure_opendir_stateless(poly_parent); ++ if (dfd == -1) { ++ pam_syslog(idata->pamh, LOG_ERR, ++ "Failed opening %s to fchdir: %m", poly_parent); ++ } ++ else if (fchdir(dfd) == -1) { + pam_syslog(idata->pamh, LOG_ERR, +- "Can't chdir to %s, %m", poly_parent); ++ "Failed fchdir to %s: %m", poly_parent); + } ++ if (dfd != -1) ++ close(dfd); + } + +- if (umount(pptr->rdir) < 0) { ++ if (secure_umount(pptr->rdir) < 0) { + int saved_errno = errno; + pam_syslog(idata->pamh, LOG_ERR, "Unmount of %s failed, %m", + pptr->rdir); +@@ -2066,7 +2323,7 @@ static int orig_namespace(struct instanc + "Unmounting instance dir for user %d & dir %s", + idata->uid, pptr->dir); + +- if (umount(pptr->dir) < 0) { ++ if (secure_umount(pptr->dir) < 0) { + pam_syslog(idata->pamh, LOG_ERR, "Unmount of %s failed, %m", + pptr->dir); + return PAM_SESSION_ERR; +--- a/modules/pam_namespace/pam_namespace.h ++++ b/modules/pam_namespace/pam_namespace.h +@@ -51,6 +51,7 @@ + #include + #include + #include ++#include + #include + #include + #include +@@ -122,6 +123,13 @@ + #define NAMESPACE_PROTECT_DATA "pam_namespace:protect_data" + + /* ++ * Operation mode for function secure_opendir() ++ */ ++#define SECURE_OPENDIR_PROTECT 0x00000001 ++#define SECURE_OPENDIR_MKDIR 0x00000002 ++#define SECURE_OPENDIR_FULL_FD 0x00000004 ++ ++/* + * Polyinstantiation method options, based on user, security context + * or both + */ +@@ -158,6 +166,9 @@ struct polydir_s { + char dir[PATH_MAX]; /* directory to polyinstantiate */ + char rdir[PATH_MAX]; /* directory to unmount (based on RUSER) */ + char instance_prefix[PATH_MAX]; /* prefix for instance dir path name */ ++ char instance_absolute[PATH_MAX]; /* absolute path to the instance dir (instance_parent + instname) */ ++ char instance_parent[PATH_MAX]; /* parent dir of the instance dir */ ++ char *instname; /* last segment of the path to the instance dir */ + enum polymethod method; /* method used to polyinstantiate */ + unsigned int num_uids; /* number of override uids */ + uid_t *uid; /* list of override uids */ diff --git a/0006-FIX-CVE-2025-6020-2.patch b/0006-FIX-CVE-2025-6020-2.patch new file mode 100644 index 0000000000000000000000000000000000000000..c9a6e393d77bc5f8802547f472b12742df7b6dba --- /dev/null +++ b/0006-FIX-CVE-2025-6020-2.patch @@ -0,0 +1,180 @@ +From a195c0daaba325aa09180b9492bf78ba03c5af89 Mon Sep 17 00:00:00 2001 +From: Olivier Bal-Petre +Date: Tue, 4 Mar 2025 14:37:02 +0100 +Subject: [PATCH 2/3] pam_namespace: add flags to indicate path safety + +Add two flags in the script to indicate if the paths to the polydir +and the instance directories are safe (root owned and writable by +root only). + +Signed-off-by: Olivier Bal-Petre +Signed-off-by: Dmitry V. Levin + +Conflict:NA +Reference:https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/pam/1.5.3-5ubuntu5.4/pam_1.5.3-5ubuntu5.4.debian.tar.xz + +--- + modules/pam_namespace/namespace.init | 56 ++++++++++++------- + modules/pam_namespace/pam_namespace.c | 79 ++++++++++++++++++++++++++- + 2 files changed, 115 insertions(+), 20 deletions(-) + +--- a/modules/pam_namespace/namespace.init ++++ b/modules/pam_namespace/namespace.init +@@ -1,25 +1,43 @@ + #!/bin/sh +-# It receives polydir path as $1, the instance path as $2, +-# a flag whether the instance dir was newly created (0 - no, 1 - yes) in $3, +-# and user name in $4. ++# It receives as arguments: ++# - $1 polydir path (see WARNING below) ++# - $2 instance path (see WARNING below) ++# - $3 flag whether the instance dir was newly created (0 - no, 1 - yes) ++# - $4 user name ++# - $5 flag whether the polydir path ($1) is safe (0 - unsafe, 1 -safe) ++# - $6 flag whether the instance path ($2) is safe (0 - unsafe, 1 - safe) ++# ++# WARNING: This script is invoked with full root privileges. Accessing ++# the polydir ($1) and the instance ($2) directories in this context may be ++# extremely dangerous as those can be under user control. The flags $5 and $6 ++# are provided to let you know if all the segments part of the path (except the ++# last one) are owned by root and are writable by root only. If the path does ++# not meet these criteria, you expose yourself to possible symlink attacks when ++# accessing these path. ++# However, even if the path components are safe, the content of the ++# directories may still be owned/writable by a user, so care must be taken! + # + # The following section will copy the contents of /etc/skel if this is a + # newly created home directory. +-if [ "$3" = 1 ]; then +- # This line will fix the labeling on all newly created directories +- [ -x /sbin/restorecon ] && /sbin/restorecon "$1" +- user="$4" +- passwd=$(getent passwd "$user") +- homedir=$(echo "$passwd" | cut -f6 -d":") +- if [ "$1" = "$homedir" ]; then +- gid=$(echo "$passwd" | cut -f4 -d":") +- cp -rT /etc/skel "$homedir" +- chown -R "$user":"$gid" "$homedir" +- mask=$(sed -E -n 's/^UMASK[[:space:]]+([^#[:space:]]+).*/\1/p' /etc/login.defs) +- mode=$(printf "%o" $((0777 & ~mask))) +- chmod ${mode:-700} "$homedir" +- [ -x /sbin/restorecon ] && /sbin/restorecon -R "$homedir" +- fi +-fi + ++# Executes only if the polydir path is safe ++if [ "$5" = 1 ]; then ++ ++ if [ "$3" = 1 ]; then ++ # This line will fix the labeling on all newly created directories ++ [ -x /sbin/restorecon ] && /sbin/restorecon "$1" ++ user="$4" ++ passwd=$(getent passwd "$user") ++ homedir=$(echo "$passwd" | cut -f6 -d":") ++ if [ "$1" = "$homedir" ]; then ++ gid=$(echo "$passwd" | cut -f4 -d":") ++ cp -rT /etc/skel "$homedir" ++ chown -R "$user":"$gid" "$homedir" ++ mask=$(sed -E -n 's/^UMASK[[:space:]]+([^#[:space:]]+).*/\1/p' /etc/login.defs) ++ mode=$(printf "%o" $((0777 & ~mask))) ++ chmod ${mode:-700} "$homedir" ++ [ -x /sbin/restorecon ] && /sbin/restorecon -R "$homedir" ++ fi ++ fi ++fi + exit 0 +--- a/modules/pam_namespace/pam_namespace.c ++++ b/modules/pam_namespace/pam_namespace.c +@@ -1495,6 +1495,79 @@ static int check_inst_parent(int dfd, st + } + + /* ++ * Check for a given absolute path that all segments except the last one are: ++ * 1. a directory owned by root and not writable by group or others ++ * 2. a symlink owned by root and referencing a directory respecting 1. ++ * Returns 0 if safe, -1 is unsafe. ++ * If the path is not accessible (does not exist, hidden under a mount...), ++ * returns -1 (unsafe). ++ */ ++static int check_safe_path(const char *path, struct instance_data *idata) ++{ ++ char *p = strdup(path); ++ char *d; ++ char *dir = p; ++ struct stat st; ++ ++ if (p == NULL) ++ return -1; ++ ++ /* Check path is absolute */ ++ if (p[0] != '/') ++ goto error; ++ ++ strip_trailing_slashes(p); ++ ++ /* Last segment of the path may be owned by the user */ ++ if ((d = strrchr(dir, '/')) != NULL) ++ *d = '\0'; ++ ++ while ((d=strrchr(dir, '/')) != NULL) { ++ ++ /* Do not follow symlinks */ ++ if (lstat(dir, &st) != 0) ++ goto error; ++ ++ if (S_ISLNK(st.st_mode)) { ++ if (st.st_uid != 0) { ++ if (idata->flags & PAMNS_DEBUG) ++ pam_syslog(idata->pamh, LOG_DEBUG, ++ "Path deemed unsafe: Symlink %s should be owned by root", dir); ++ goto error; ++ } ++ ++ /* Follow symlinks */ ++ if (stat(dir, &st) != 0) ++ goto error; ++ } ++ ++ if (!S_ISDIR(st.st_mode)) { ++ if (idata->flags & PAMNS_DEBUG) ++ pam_syslog(idata->pamh, LOG_DEBUG, ++ "Path deemed unsafe: %s is expected to be a directory", dir); ++ goto error; ++ } ++ ++ if (st.st_uid != 0 || ++ ((st.st_mode & (S_IWGRP|S_IWOTH)) && !(st.st_mode & S_ISVTX))) { ++ if (idata->flags & PAMNS_DEBUG) ++ pam_syslog(idata->pamh, LOG_DEBUG, ++ "Path deemed unsafe: %s should be owned by root, and not be writable by group or others", dir); ++ goto error; ++ } ++ ++ *d = '\0'; ++ } ++ ++ free(p); ++ return 0; ++ ++error: ++ free(p); ++ return -1; ++} ++ ++/* + * Check to see if there is a namespace initialization script in + * the /etc/security directory. If such a script exists + * execute it and pass directory to polyinstantiate and instance +@@ -1553,7 +1626,11 @@ static int inst_init(const struct polydi + } + + execle(init_script, init_script, +- polyptr->dir, ipath, newdir?"1":"0", idata->user, NULL, envp); ++ polyptr->dir, ipath, ++ newdir ? "1":"0", idata->user, ++ (check_safe_path(polyptr->dir, idata) == -1) ? "0":"1", ++ (check_safe_path(ipath, idata) == -1) ? "0":"1", ++ NULL, envp); + _exit(1); + } else if (pid > 0) { + while (((rc = waitpid(pid, &status, 0)) == (pid_t)-1) && diff --git a/0006-FIX-CVE-2025-6020-3.patch b/0006-FIX-CVE-2025-6020-3.patch new file mode 100644 index 0000000000000000000000000000000000000000..7f43a1377dbfcd69add5817e3d858275b22ca537 --- /dev/null +++ b/0006-FIX-CVE-2025-6020-3.patch @@ -0,0 +1,30 @@ +From 2c978bab94a0a62e5b8bc0d52a777dca394d90cb Mon Sep 17 00:00:00 2001 +From: "Dmitry V. Levin" +Date: Tue, 27 May 2025 08:00:00 +0000 +Subject: [PATCH 3/3] pam_namespace: secure_opendir: do not look at the group + ownership + +When the directory is not group-writable, the group ownership does +not matter, and when it is group-writable, there should not be any +exceptions for the root group as there is no guarantee that the root +group does not include non-root users. + +Conflict:NA +Reference:https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/pam/1.5.3-5ubuntu5.4/pam_1.5.3-5ubuntu5.4.debian.tar.xz + +--- + modules/pam_namespace/pam_namespace.c | 3 +-- + 1 file changed, 1 insertion(+), 2 deletions(-) + +--- a/modules/pam_namespace/pam_namespace.c ++++ b/modules/pam_namespace/pam_namespace.c +@@ -243,8 +243,7 @@ static int secure_opendir(const char *pa + if (dfd_next == -1) + goto error; + } else if (st.st_uid != 0 +- || (st.st_gid != 0 && (st.st_mode & S_IWGRP)) +- || (st.st_mode & S_IWOTH)) { ++ || (st.st_mode & (S_IWGRP|S_IWOTH))) { + /* do not follow symlinks on subdirectories */ + flags |= O_NOFOLLOW; + } diff --git a/pam.spec b/pam.spec index 855f735de9e1e7391f9e04b5e0aafee6e7da0132..ac5e68ad866b0015578f6779eed478e6f71cb03f 100644 --- a/pam.spec +++ b/pam.spec @@ -1,4 +1,4 @@ -%define anolis_release 2 +%define anolis_release 3 %global soname_version 0 Name: pam @@ -31,6 +31,30 @@ Patch2: 0001-change-ndbm-to-gdbm.patch Patch3: 0001-add-sm3-crypt-support.patch # https://github.com/linux-pam/linux-pam/pull/686/commits/b3020da7da384d769f27a8713257fbe1001878be Patch4: 0002-Fix-CVE-2024-10041.patch +# https://github.com/linux-pam/linux-pam/commit/23393bef92c1e768eda329813d7af55481c6ca9f +# https://github.com/linux-pam/linux-pam/commit/940747f88c16e029b69a74e80a2e94f65cb3e628 +Patch5: 0003-Fix-CVE-2024-10963.patch +# https://github.com/linux-pam/linux-pam/commit/031bb5a5d0d950253b68138b498dc93be69a64cb +Patch6: 0004-FIX-CVE-2024-22365.patch +Patch7: pam_namespace_170.patch +Patch8: pam_namespace_post170-01.patch +Patch9: pam_namespace_post170-02.patch +Patch10: pam_namespace_post170-03.patch +Patch11: pam_namespace_post170-04.patch +Patch12: pam_namespace_post170-05.patch +Patch13: pam_namespace_post170-06.patch +Patch14: pam_namespace_post170-07.patch +Patch15: pam_namespace_post170-08.patch +Patch16: pam_namespace_post170-09.patch +Patch17: pam_namespace_post170-10.patch +Patch18: pam_namespace_post170-11.patch +Patch19: pam_namespace_post170-12.patch +Patch20: pam_namespace_post170-13.patch +Patch21: pam_namespace_post170-14.patch +Patch22: pam_namespace_revert_abi.patch +Patch23: 0006-FIX-CVE-2025-6020-1.patch +Patch24: 0006-FIX-CVE-2025-6020-2.patch +Patch25: 0006-FIX-CVE-2025-6020-3.patch BuildRequires: audit-libs-devel BuildRequires: autoconf @@ -345,6 +369,9 @@ done %{abidir}/libpam*.dump %changelog +* Tue Aug 19 2025 wh02252983 - 1.5.3-3 +- add patch to Fix CVE-2024-10963 CVE-2024-22365 CVE-2025-6020 + * Tue May 20 2025 wenxin - 1.5.3-2 - Fix CVE-2024-10041 diff --git a/pam_namespace_170.patch b/pam_namespace_170.patch new file mode 100644 index 0000000000000000000000000000000000000000..30a0a381750c9a76c189c4e290f67dd3f148712b --- /dev/null +++ b/pam_namespace_170.patch @@ -0,0 +1,338 @@ +From 971a74d79b48a19ff1446642f39b3c5a8a7db247 Mon Sep 17 00:00:00 2001 +From: Marc Deslauriers