Resolves: RHEL-144817, CVE-2026-23893 Privilege Escalation or Data Exposure via Symlink Following

opencryptoki-3.20.0-CVE-3-2026-23893.patch

@@ -0,0 +1,499 @@
+commit b3392430af1fe260386d609c967f514679d218a4
+Author: Pavel Kohout <pavel@aisle.com>
+Date:   Tue Jan 13 00:00:00 2026 +0000
+
+    Fix symlink-following vulnerabilities (CWE-59)
+    
+    Multiple symlink-following vulnerabilities exist in OpenCryptoki that run
+    in privileged contexts. These allow a token-group user to redirect file
+    operations to arbitrary filesystem targets by planting symlinks in
+    group-writable token directories, resulting in privilege escalation or
+    data exposure.
+    
+    Affected components:
+    1. pkcstok_migrate: fopen() follows symlinks, then set_perm() modifies the
+       target permissions.
+    2. loadsave.c: Multiple wrapper functions use fopen() followed by set_perm().
+    3. hsm_mk_change.c: hsm_mk_change_op_open() uses fopen() followed by
+       hsm_mk_change_op_set_perm().
+    4. pbkdf.c: fopen() followed by set_perms() in two locations.
+    
+    This fix:
+    - Introduces fopen_nofollow() helper in platform.h
+    - Checks for O_NOFOLLOW at compile time (not hardcoded per-platform)
+    - On platforms with O_NOFOLLOW: uses open(O_NOFOLLOW) + fdopen() for atomic
+      symlink rejection (race-condition free)
+    - On platforms without O_NOFOLLOW: falls back to lstat() + fopen() and emits
+      a compiler warning so the unsafe fallback doesn't go unnoticed
+    - Updates all affected wrapper functions to use fopen_nofollow()
+    
+    Reported-by: Pavel Kohout, Aisle Research, www.aisle.com
+    Signed-off-by: Pavel Kohout <pavel@aisle.com>
+    Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
+
+diff --git a/usr/lib/common/loadsave.c b/usr/lib/common/loadsave.c
+index 09553b51..352a71dc 100644
+--- a/usr/lib/common/loadsave.c
++++ b/usr/lib/common/loadsave.c
+@@ -42,6 +42,7 @@
+ #include "trace.h"
+ #include "ock_syslog.h"
+ #include "slotmgr.h" // for ock_snprintf
++#include "platform.h"
+ 
+ extern void set_perm(int);
+ 
+@@ -67,9 +68,17 @@ static FILE *open_token_object_path(char *buf, size_t buflen,
+                                     STDLL_TokData_t *tokdata, char *path,
+                                     char *mode)
+ {
++    FILE *fp;
++
+     if (get_token_object_path(buf, buflen, tokdata, path) < 0)
+         return NULL;
+-    return fopen(buf, mode);
++
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(buf, mode);
++    if (fp == NULL && errno == ELOOP)
++        TRACE_ERROR("Refusing to follow symlink: %s\n", buf);
++
++    return fp;
+ }
+ 
+ static int get_token_data_store_path(char *buf, size_t buflen,
+@@ -86,9 +95,17 @@ static FILE *open_token_data_store_path(char *buf, size_t buflen,
+                                         STDLL_TokData_t *tokdata, char *path,
+                                         char *mode)
+ {
++    FILE *fp;
++
+     if (get_token_data_store_path(buf, buflen, tokdata, path) < 0)
+         return NULL;
+-    return fopen(buf, mode);
++
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(buf, mode);
++    if (fp == NULL && errno == ELOOP)
++        TRACE_ERROR("Refusing to follow symlink: %s\n", buf);
++
++    return fp;
+ }
+ 
+ static FILE *open_token_object_index(char *buf, size_t buflen,
+@@ -100,11 +117,19 @@ static FILE *open_token_object_index(char *buf, size_t buflen,
+ static FILE *open_token_nvdat(char *buf, size_t buflen,
+                               STDLL_TokData_t *tokdata, char *mode)
+ {
++    FILE *fp;
++
+     if (ock_snprintf(buf, buflen, "%s/" PK_LITE_NV, tokdata->data_store)) {
+         TRACE_ERROR("NVDAT.TOK file name buffer overflow\n");
+         return NULL;
+     }
+-    return fopen(buf, mode);
++
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(buf, mode);
++    if (fp == NULL && errno == ELOOP)
++        TRACE_ERROR("Refusing to follow symlink: %s\n", buf);
++
++    return fp;
+ }
+ 
+ char *get_pk_dir(STDLL_TokData_t *tokdata, char *fname, size_t len)
+@@ -185,9 +210,12 @@ CK_RV save_token_object(STDLL_TokData_t *tokdata, OBJECT *obj)
+     // we didn't find it...either the index file doesn't exist or this
+     // is a new object...
+     //
+-    fp = fopen(fname, "a");
++    fp = fopen_nofollow(fname, "a");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         return CKR_FUNCTION_FAILED;
+     }
+ 
+@@ -237,8 +265,12 @@ CK_RV delete_token_object(STDLL_TokData_t *tokdata, OBJECT *obj)
+ 
+     fclose(fp1);
+     fclose(fp2);
+-    fp2 = fopen(objidx, "w");
+-    fp1 = fopen(idxtmp, "r");
++    fp2 = fopen_nofollow(objidx, "w");
++    if (fp1 == NULL && errno == ELOOP)
++        TRACE_ERROR("Refusing to follow symlink: %s\n", objidx);
++    fp1 = fopen_nofollow(idxtmp, "r");
++    if (fp2 == NULL && errno == ELOOP)
++        TRACE_ERROR("Refusing to follow symlink: %s\n", idxtmp);
+     if (!fp1 || !fp2) {
+         if (fp1)
+             fclose(fp1);
+@@ -526,11 +558,14 @@ CK_RV load_token_data_old(STDLL_TokData_t *tokdata, CK_SLOT_ID slot_id)
+         if (errno == ENOENT) {
+             init_token_data(tokdata, slot_id);
+ 
+-            fp = fopen(fname, "r");
++            fp = fopen_nofollow(fname, "r");
+             if (!fp) {
+                 // were really hosed here since the created
+                 // did not occur
+-                TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++                if (errno == ELOOP)
++                    TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++                else
++                    TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+                 rc = CKR_FUNCTION_FAILED;
+                 goto out_unlock;
+             }
+@@ -730,9 +765,12 @@ static CK_RV save_private_token_object_old(STDLL_TokData_t *tokdata, OBJECT *obj
+         rc = CKR_FUNCTION_FAILED;
+         goto error;
+     }
+-    fp = fopen(fname, "w");
++    fp = fopen_nofollow(fname, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto error;
+     }
+@@ -1483,9 +1521,12 @@ CK_RV reload_token_object_old(STDLL_TokData_t *tokdata, OBJECT *obj)
+         rc = CKR_FUNCTION_FAILED;
+         goto done;
+     }
+-    fp = fopen(fname, "r");
++    fp = fopen_nofollow(fname, "r");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto done;
+     }
+@@ -1572,9 +1613,12 @@ CK_RV save_public_token_object_old(STDLL_TokData_t *tokdata, OBJECT * obj)
+         rc = CKR_FUNCTION_FAILED;
+         goto error;
+     }
+-    fp = fopen(fname, "w");
++    fp = fopen_nofollow(fname, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto error;
+     }
+@@ -2179,11 +2223,14 @@ CK_RV load_token_data(STDLL_TokData_t *tokdata, CK_SLOT_ID slot_id)
+         if (errno == ENOENT) {
+             init_token_data(tokdata, slot_id);
+ 
+-            fp = fopen(fname, "r");
++            fp = fopen_nofollow(fname, "r");
+             if (!fp) {
+                 // were really hosed here since the created
+                 // did not occur
+-                TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++                if (errno == ELOOP)
++                    TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++                else
++                    TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+                 rc = CKR_FUNCTION_FAILED;
+                 goto out_unlock;
+             }
+@@ -2355,7 +2402,7 @@ CK_RV save_private_token_object(STDLL_TokData_t *tokdata, OBJECT *obj)
+         goto done;
+     }
+ 
+-    fp = fopen(fname, "r");
++    fp = fopen_nofollow(fname, "r");
+     if (fp == NULL) {
+         /* create new token object */
+         new = 1;
+@@ -2453,9 +2500,12 @@ do_work:
+     if (rc != CKR_OK)
+         goto done;
+ 
+-    fp = fopen(fname, "w");
++    fp = fopen_nofollow(fname, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto done;
+     }
+@@ -2650,9 +2700,12 @@ CK_RV reload_token_object(STDLL_TokData_t *tokdata, OBJECT *obj)
+     sprintf(fname, "%s/%s/", tokdata->data_store, PK_LITE_OBJ_DIR);
+     strncat(fname, (char *) obj->name, 8);
+ 
+-    fp = fopen(fname, "r");
++    fp = fopen_nofollow(fname, "r");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto done;
+     }
+@@ -2763,9 +2816,12 @@ CK_RV save_public_token_object(STDLL_TokData_t *tokdata, OBJECT *obj)
+     sprintf(fname, "%s/%s/", tokdata->data_store, PK_LITE_OBJ_DIR);
+     strncat(fname, (char *) obj->name, 8);
+ 
+-    fp = fopen(fname, "w");
++    fp = fopen_nofollow(fname, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen(%s): %s\n", fname, strerror(errno));
+         rc = CKR_FUNCTION_FAILED;
+         goto done;
+     }
+@@ -2823,9 +2879,12 @@ CK_RV load_public_token_objects(STDLL_TokData_t *tokdata)
+         sprintf(fname, "%s/%s/", tokdata->data_store, PK_LITE_OBJ_DIR);
+         strcat(fname, tmp);
+ 
+-        fp2 = fopen(fname, "r");
+-        if (!fp2)
++        fp2 = fopen_nofollow(fname, "r");
++        if (!fp2) {
++            if (errno == ELOOP)
++                TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
+             continue;
++        }
+ 
+         if (fread(header, PUB_HEADER_LEN, 1, fp2) != 1) {
+             fclose(fp2);
+diff --git a/usr/lib/common/platform.h b/usr/lib/common/platform.h
+new file mode 100644
+index 00000000..b3e5473b
+--- /dev/null
++++ b/usr/lib/common/platform.h
+@@ -0,0 +1,91 @@
++/*
++ * COPYRIGHT (c) International Business Machines Corp. 2024
++ *
++ * This program is provided under the terms of the Common Public License,
++ * version 1.0 (CPL-1.0). Any use, reproduction or distribution for this
++ * software constitutes recipient's acceptance of CPL-1.0 terms which can be
++ * found in the file LICENSE file or at
++ * https://opensource.org/licenses/cpl1.0.php
++ */
++#ifndef PLATFORM_H
++#define PLATFORM_H
++
++#include <dlfcn.h>
++#include <stdio.h>
++#include <fcntl.h>
++#include <unistd.h>
++#include <string.h>
++#include <errno.h>
++#include <sys/stat.h>
++
++/*
++ * Check for O_NOFOLLOW support at compile time.
++ * If not available, fall back to lstat() + fopen() (has TOCTOU race).
++ */
++#ifndef O_NOFOLLOW
++#define OCK_NO_O_NOFOLLOW 1
++#warning "O_NOFOLLOW not supported, symlink protection uses racy lstat() fallback!"
++#endif
++
++/*
++ * CWE-59 fix: Open file without following symlinks.
++ *
++ * On platforms with O_NOFOLLOW support:
++ *   Uses open(O_NOFOLLOW) + fdopen() for atomic symlink rejection.
++ *
++ * On platforms without O_NOFOLLOW (e.g., older AIX):
++ *   Falls back to lstat() + fopen(). This has a TOCTOU race condition,
++ *   but still catches pre-planted symlinks which is the common attack
++ *   scenario. Better than no protection at all.
++ *
++ * Returns NULL with errno=ELOOP if path is a symlink.
++ */
++static inline FILE *fopen_nofollow(const char *path, const char *mode)
++{
++#ifdef OCK_NO_O_NOFOLLOW
++    /*
++     * Fallback for platforms without O_NOFOLLOW: use lstat() check.
++     * This has a TOCTOU race but catches pre-planted symlinks.
++     */
++    struct stat sb;
++
++    if (lstat(path, &sb) == 0) {
++        if (S_ISLNK(sb.st_mode)) {
++            errno = ELOOP;
++            return NULL;
++        }
++    }
++    /* Note: if lstat fails (e.g., file doesn't exist for "w" mode),
++     * we proceed with fopen() which will handle the error appropriately */
++    return fopen(path, mode);
++#else
++    /* Preferred: atomic symlink rejection via O_NOFOLLOW */
++    int flags = O_NOFOLLOW;
++    int fd;
++    FILE *fp;
++
++    /* Determine flags based on mode */
++    if (mode[0] == 'r') {
++        flags |= (mode[1] == '+') ? O_RDWR : O_RDONLY;
++    } else if (mode[0] == 'w') {
++        flags |= O_CREAT | O_TRUNC | ((mode[1] == '+') ? O_RDWR : O_WRONLY);
++    } else if (mode[0] == 'a') {
++        flags |= O_CREAT | O_APPEND | ((mode[1] == '+') ? O_RDWR : O_WRONLY);
++    } else {
++        return NULL;
++    }
++
++    fd = open(path, flags, 0600);
++    if (fd < 0)
++        return NULL;
++
++    fp = fdopen(fd, mode);
++    if (fp == NULL) {
++        close(fd);
++        return NULL;
++    }
++    return fp;
++#endif
++}
++
++#endif /* PLATFORM_H */
+diff --git a/usr/lib/hsm_mk_change/hsm_mk_change.c b/usr/lib/hsm_mk_change/hsm_mk_change.c
+index 6c032965..bbdd94c2 100644
+--- a/usr/lib/hsm_mk_change/hsm_mk_change.c
++++ b/usr/lib/hsm_mk_change/hsm_mk_change.c
+@@ -29,6 +29,7 @@
+ #endif
+ #include "hsm_mk_change.h"
+ #include "pkcs32.h"
++#include "platform.h"
+ 
+ struct hsm_mk_change_op_hdr {
+     char id[6];
+@@ -611,9 +612,13 @@ static FILE* hsm_mk_change_op_open(const char *id, CK_SLOT_ID slot_id,
+ 
+     TRACE_DEVEL("file to open: %s mode: %s\n", hsm_mk_change_file, mode);
+ 
+-    fp = fopen(hsm_mk_change_file, mode);
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(hsm_mk_change_file, mode);
+     if (fp == NULL) {
+-        TRACE_ERROR("%s fopen(%s, %s): %s\n", __func__,
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", hsm_mk_change_file);
++        else
++            TRACE_ERROR("%s fopen(%s, %s): %s\n", __func__,
+                         hsm_mk_change_file, mode, strerror(errno));
+     }
+ 
+diff --git a/usr/lib/icsf_stdll/pbkdf.c b/usr/lib/icsf_stdll/pbkdf.c
+index abf9ff13..e50fe4e2 100644
+--- a/usr/lib/icsf_stdll/pbkdf.c
++++ b/usr/lib/icsf_stdll/pbkdf.c
+@@ -27,6 +27,7 @@
+ #include "h_extern.h"
+ #include "pbkdf.h"
+ #include "trace.h"
++#include "platform.h"
+ 
+ 
+ CK_RV get_randombytes(unsigned char *output, int bytes)
+@@ -527,9 +528,13 @@ CK_RV secure_racf(STDLL_TokData_t *tokdata,
+     /* get the total length */
+     totallen = outputlen + AES_INIT_VECTOR_SIZE;
+ 
+-    fp = fopen(RACFFILE, "w");
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(RACFFILE, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen failed: %s\n", strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", RACFFILE);
++        else
++            TRACE_ERROR("fopen failed: %s\n", strerror(errno));
+         return CKR_FUNCTION_FAILED;
+     }
+ 
+@@ -600,9 +605,13 @@ CK_RV secure_masterkey(STDLL_TokData_t *tokdata,
+     /* get the total length */
+     totallen = outputlen + SALTSIZE;
+ 
+-    fp = fopen(fname, "w");
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    fp = fopen_nofollow(fname, "w");
+     if (!fp) {
+-        TRACE_ERROR("fopen failed: %s\n", strerror(errno));
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", fname);
++        else
++            TRACE_ERROR("fopen failed: %s\n", strerror(errno));
+         return CKR_FUNCTION_FAILED;
+     }
+ 
+diff --git a/usr/sbin/pkcstok_migrate/pkcstok_migrate.c b/usr/sbin/pkcstok_migrate/pkcstok_migrate.c
+index a9777a3c..84988b2c 100644
+--- a/usr/sbin/pkcstok_migrate/pkcstok_migrate.c
++++ b/usr/sbin/pkcstok_migrate/pkcstok_migrate.c
+@@ -41,6 +41,7 @@
+ #include "local_types.h"
+ #include "h_extern.h"
+ #include "slotmgr.h" // for ock_snprintf
++#include "platform.h"
+ 
+ #define OCK_TOOL
+ #include "pkcs_utils.h"
+@@ -70,9 +71,14 @@ static FILE *open_datastore_file(char *buf, size_t buflen,
+         TRACE_ERROR("Path overflow for datastore file %s\n", file);
+         return NULL;
+     }
+-    res = fopen(buf, mode);
+-    if (!res)
+-        TRACE_ERROR("fopen(%s) failed, errno=%s\n", buf, strerror(errno));
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    res = fopen_nofollow(buf, mode);
++    if (!res) {
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", buf);
++        else
++            TRACE_ERROR("fopen(%s) failed, errno=%s\n", buf, strerror(errno));
++    }
+     return res;
+ }
+ 
+@@ -87,9 +93,14 @@ static FILE *open_tokenobject(char *buf, size_t buflen,
+                     file, tokenobj);
+         return NULL;
+     }
+-    res = fopen(buf, mode);
+-    if (!res)
+-        TRACE_ERROR("fopen(%s) failed, errno=%s\n", buf, strerror(errno));
++    /* CWE-59 fix: Use fopen_nofollow to prevent symlink attacks */
++    res = fopen_nofollow(buf, mode);
++    if (!res) {
++        if (errno == ELOOP)
++            TRACE_ERROR("Refusing to follow symlink: %s\n", buf);
++        else
++            TRACE_ERROR("fopen(%s) failed, errno=%s\n", buf, strerror(errno));
++    }
+     return res;
+ }
+ 

opencryptoki.spec

@@ -1,7 +1,7 @@
 Name: opencryptoki
 Summary: Implementation of the PKCS#11 (Cryptoki) specification v3.0
 Version: 3.22.0
-Release: 3%{?dist}.1
+Release: 3%{?dist}.2
 License: CPL
 Group: System Environment/Base
 URL: https://github.com/opencryptoki/opencryptoki
@@ -23,6 +23,8 @@ Patch23: opencryptoki-CVE-2024-0914-part4.patch
 Patch24: opencryptoki-CVE-2024-0914-part5.patch
 # supporting CCA 8.4
 Patch25: 3.22-CCA-Adjust-CCA-host-library-version-detection-for-ne.patch
+# CVE-3-2026-23893, symlink-following vulnerabilities
+Patch26: opencryptoki-3.20.0-CVE-3-2026-23893.patch
 
 Requires(pre): coreutils diffutils
 Requires: (selinux-policy >= 3.14.3-121 if selinux-policy-targeted)
@@ -383,6 +385,9 @@ fi
 
 
 %changelog
+* Mon Mar 02 2026 Than Ngo <than@redhat.com> - 3.22.0-3.2
+- Resolves: RHEL-144817, CVE-2026-23893 Privilege Escalation or Data Exposure via Symlink Following
+
 * Mon Aug 11 2025 Than Ngo <than@redhat.com> - 3.22.0-3.1
 - Resolves: RHEL-105918, fix for supporting CCA 8.4