From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: linux-security-module@vger.kernel.org,
"Luis R. Rodriguez" <mcgrof@suse.com>,
kexec@lists.infradead.org, linux-modules@vger.kernel.org,
fsdevel@vger.kernel.org, David Howells <dhowells@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Kees Cook <keescook@chromium.org>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
Eric Biederman <ebiederm@xmission.com>,
Rusty Russell <rusty@rustcorp.com.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Subject: [PATCH v3 16/22] module: replace copy_module_from_fd with kernel version
Date: Wed, 3 Feb 2016 14:06:24 -0500 [thread overview]
Message-ID: <1454526390-19792-17-git-send-email-zohar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1454526390-19792-1-git-send-email-zohar@linux.vnet.ibm.com>
Replace copy_module_from_fd() with kernel_read_file_from_fd().
Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.
The security function security_kernel_module_from_file() was called prior
to reading a kernel module. Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook. Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.
This patch removes the security_kernel_module_from_file() hook and security
call.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
include/linux/fs.h | 1 +
include/linux/ima.h | 6 ----
include/linux/lsm_hooks.h | 7 ----
include/linux/security.h | 5 ---
kernel/module.c | 68 +++++----------------------------------
security/integrity/ima/ima_main.c | 35 ++++++++------------
security/security.c | 12 -------
7 files changed, 22 insertions(+), 112 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5ba806b..9e1f1e3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2528,6 +2528,7 @@ extern int do_pipe_flags(int *, int);
enum kernel_read_file_id {
READING_FIRMWARE = 1,
+ READING_MODULE,
READING_MAX_ID
};
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 6adcaea..e6516cb 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -18,7 +18,6 @@ extern int ima_bprm_check(struct linux_binprm *bprm);
extern int ima_file_check(struct file *file, int mask, int opened);
extern void ima_file_free(struct file *file);
extern int ima_file_mmap(struct file *file, unsigned long prot);
-extern int ima_module_check(struct file *file);
extern int ima_read_file(struct file *file, enum kernel_read_file_id id);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
@@ -44,11 +43,6 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot)
return 0;
}
-static inline int ima_module_check(struct file *file)
-{
- return 0;
-}
-
static inline int ima_read_file(struct file *file, enum kernel_read_file_id id)
{
return 0;
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index d32b7bd..cdee11c 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -546,12 +546,6 @@
* userspace to load a kernel module with the given name.
* @kmod_name name of the module requested by the kernel
* Return 0 if successful.
- * @kernel_module_from_file:
- * Load a kernel module from userspace.
- * @file contains the file structure pointing to the file containing
- * the kernel module to load. If the module is being loaded from a blob,
- * this argument will be NULL.
- * Return 0 if permission is granted.
* @kernel_read_file:
* Read a file specified by userspace.
* @file contains the file structure pointing to the file being read
@@ -1725,7 +1719,6 @@ struct security_hook_heads {
struct list_head kernel_read_file;
struct list_head kernel_post_read_file;
struct list_head kernel_module_request;
- struct list_head kernel_module_from_file;
struct list_head task_fix_setuid;
struct list_head task_setpgid;
struct list_head task_getpgid;
diff --git a/include/linux/security.h b/include/linux/security.h
index 071fb74..157f0cb 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -859,11 +859,6 @@ static inline int security_kernel_module_request(char *kmod_name)
return 0;
}
-static inline int security_kernel_module_from_file(struct file *file)
-{
- return 0;
-}
-
static inline int security_kernel_read_file(struct file *file,
enum kernel_read_file_id id)
{
diff --git a/kernel/module.c b/kernel/module.c
index 8f051a1..d77c4f1 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2665,7 +2665,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
if (info->len < sizeof(*(info->hdr)))
return -ENOEXEC;
- err = security_kernel_module_from_file(NULL);
+ err = security_kernel_read_file(NULL, READING_MODULE);
if (err)
return err;
@@ -2683,63 +2683,6 @@ static int copy_module_from_user(const void __user *umod, unsigned long len,
return 0;
}
-/* Sets info->hdr and info->len. */
-static int copy_module_from_fd(int fd, struct load_info *info)
-{
- struct fd f = fdget(fd);
- int err;
- struct kstat stat;
- loff_t pos;
- ssize_t bytes = 0;
-
- if (!f.file)
- return -ENOEXEC;
-
- err = security_kernel_module_from_file(f.file);
- if (err)
- goto out;
-
- err = vfs_getattr(&f.file->f_path, &stat);
- if (err)
- goto out;
-
- if (stat.size > INT_MAX) {
- err = -EFBIG;
- goto out;
- }
-
- /* Don't hand 0 to vmalloc, it whines. */
- if (stat.size == 0) {
- err = -EINVAL;
- goto out;
- }
-
- info->hdr = vmalloc(stat.size);
- if (!info->hdr) {
- err = -ENOMEM;
- goto out;
- }
-
- pos = 0;
- while (pos < stat.size) {
- bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
- stat.size - pos);
- if (bytes < 0) {
- vfree(info->hdr);
- err = bytes;
- goto out;
- }
- if (bytes == 0)
- break;
- pos += bytes;
- }
- info->len = pos;
-
-out:
- fdput(f);
- return err;
-}
-
static void free_copy(struct load_info *info)
{
vfree(info->hdr);
@@ -3602,8 +3545,10 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
{
- int err;
struct load_info info = { };
+ loff_t size;
+ void *hdr;
+ int err;
err = may_init_module();
if (err)
@@ -3615,9 +3560,12 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
|MODULE_INIT_IGNORE_VERMAGIC))
return -EINVAL;
- err = copy_module_from_fd(fd, &info);
+ err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
+ READING_MODULE);
if (err)
return err;
+ info.hdr = hdr;
+ info.len = size;
return load_module(&info, uargs, flags);
}
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 6f79bdf..1e91d94 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -316,28 +316,6 @@ int ima_file_check(struct file *file, int mask, int opened)
EXPORT_SYMBOL_GPL(ima_file_check);
/**
- * ima_module_check - based on policy, collect/store/appraise measurement.
- * @file: pointer to the file to be measured/appraised
- *
- * Measure/appraise kernel modules based on policy.
- *
- * On success return 0. On integrity appraisal error, assuming the file
- * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
- */
-int ima_module_check(struct file *file)
-{
- if (!file) {
-#ifndef CONFIG_MODULE_SIG_FORCE
- if ((ima_appraise & IMA_APPRAISE_MODULES) &&
- (ima_appraise & IMA_APPRAISE_ENFORCE))
- return -EACCES; /* INTEGRITY_UNKNOWN */
-#endif
- return 0; /* We rely on module signature checking */
- }
- return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0);
-}
-
-/**
* ima_read_file - pre-measure/appraise hook decision based on policy
* @file: pointer to the file to be measured/appraised/audit
* @read_id: caller identifier
@@ -350,6 +328,14 @@ int ima_module_check(struct file *file)
*/
int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
{
+ if (!file && read_id == READING_MODULE) {
+#ifndef CONFIG_MODULE_SIG_FORCE
+ if ((ima_appraise & IMA_APPRAISE_MODULES) &&
+ (ima_appraise & IMA_APPRAISE_ENFORCE))
+ return -EACCES; /* INTEGRITY_UNKNOWN */
+#endif
+ return 0; /* We rely on module signature checking */
+ }
return 0;
}
@@ -378,6 +364,9 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
return 0;
}
+ if (!file && read_id == READING_MODULE) /* MODULE_SIG_FORCE enabled */
+ return 0;
+
if (!file && (!buf || size == 0)) { /* should never happen */
if (ima_appraise & IMA_APPRAISE_ENFORCE)
return -EACCES;
@@ -386,6 +375,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
if (read_id == READING_FIRMWARE)
func = FIRMWARE_CHECK;
+ else if (read_id == READING_MODULE)
+ func = MODULE_CHECK;
return process_measurement(file, buf, size, MAY_READ, func, 0);
}
diff --git a/security/security.c b/security/security.c
index 1728fe2..3573c82 100644
--- a/security/security.c
+++ b/security/security.c
@@ -889,16 +889,6 @@ int security_kernel_module_request(char *kmod_name)
return call_int_hook(kernel_module_request, 0, kmod_name);
}
-int security_kernel_module_from_file(struct file *file)
-{
- int ret;
-
- ret = call_int_hook(kernel_module_from_file, 0, file);
- if (ret)
- return ret;
- return ima_module_check(file);
-}
-
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id)
{
int ret;
@@ -1703,8 +1693,6 @@ struct security_hook_heads security_hook_heads = {
LIST_HEAD_INIT(security_hook_heads.kernel_create_files_as),
.kernel_module_request =
LIST_HEAD_INIT(security_hook_heads.kernel_module_request),
- .kernel_module_from_file =
- LIST_HEAD_INIT(security_hook_heads.kernel_module_from_file),
.kernel_read_file =
LIST_HEAD_INIT(security_hook_heads.kernel_read_file),
.kernel_post_read_file =
--
2.1.0
next prev parent reply other threads:[~2016-02-03 19:08 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 19:06 [PATCH v3 00/22] vfs: support for a common kernel file loader Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 01/22] ima: separate 'security.ima' reading functionality from collect Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 02/22] ima: refactor ima_policy_show() to display "ima_hooks" rules Mimi Zohar
2016-02-07 19:45 ` Petko Manolov
2016-02-10 19:33 ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 03/22] ima: use "ima_hooks" enum as function argument Mimi Zohar
2016-02-07 19:46 ` Petko Manolov
2016-02-10 19:35 ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 04/22] firmware: simplify dev_*() print messages for generic helpers Mimi Zohar
2016-02-04 17:26 ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 05/22] firmware: move completing fw into a helper Mimi Zohar
2016-02-04 17:27 ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 06/22] firmware: fold successful fw read early Mimi Zohar
2016-02-04 17:36 ` Kees Cook
2016-02-04 20:26 ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 07/22] vfs: define a generic function to read a file from the kernel Mimi Zohar
2016-02-04 17:41 ` Kees Cook
2016-02-03 19:06 ` [PATCH v3 08/22] vfs: define kernel_read_file_id enumeration Mimi Zohar
2016-02-04 17:41 ` Kees Cook
2016-02-04 19:45 ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 09/22] ima: provide buffer hash calculation function Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 10/22] ima: calculate the hash of a buffer using aynchronous hash(ahash) Mimi Zohar
2016-02-10 19:58 ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 11/22] ima: define a new hook to measure and appraise a file already in memory Mimi Zohar
2016-02-10 20:27 ` Dmitry Kasatkin
2016-02-03 19:06 ` [PATCH v3 12/22] vfs: define kernel_read_file_from_path Mimi Zohar
2016-02-04 17:46 ` Kees Cook
2016-02-04 19:47 ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 13/22] firmware: replace call to fw_read_file_contents() with kernel version Mimi Zohar
2016-02-04 17:56 ` Kees Cook
2016-02-04 19:51 ` Luis R. Rodriguez
2016-02-03 19:06 ` [PATCH v3 14/22] security: define kernel_read_file hook Mimi Zohar
2016-02-04 17:57 ` Kees Cook
2016-02-04 19:54 ` Luis R. Rodriguez
2016-02-11 16:54 ` Casey Schaufler
2016-02-11 19:35 ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 15/22] vfs: define kernel_copy_file_from_fd() Mimi Zohar
2016-02-04 17:58 ` Kees Cook
2016-02-04 19:55 ` Luis R. Rodriguez
2016-02-03 19:06 ` Mimi Zohar [this message]
2016-02-04 18:04 ` [PATCH v3 16/22] module: replace copy_module_from_fd with kernel version Kees Cook
2016-02-04 19:56 ` Luis R. Rodriguez
2016-02-05 0:19 ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 17/22] ima: remove firmware and module specific cached status info Mimi Zohar
2016-02-07 19:56 ` Petko Manolov
2016-02-10 20:18 ` Dmitry Kasatkin
2016-02-10 23:14 ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 18/22] kexec: replace call to copy_file_from_fd() with kernel version Mimi Zohar
2016-02-04 18:05 ` Kees Cook
2016-02-04 19:57 ` Luis R. Rodriguez
2016-02-12 12:50 ` Dave Young
2016-02-03 19:06 ` [PATCH v3 19/22] ima: support for kexec image and initramfs Mimi Zohar
2016-02-07 20:10 ` Petko Manolov
2016-02-08 23:34 ` Mimi Zohar
2016-02-10 21:09 ` Dmitry Kasatkin
2016-02-10 23:21 ` Mimi Zohar
[not found] ` <CACE9dm8OJ1cgbKszUG-pCiEMVarUFLLWi_jewVV-JEMGAJsA-g@mail.gmail.com>
2016-02-11 2:08 ` Mimi Zohar
2016-02-11 8:47 ` Dmitry Kasatkin
2016-02-11 12:16 ` Mimi Zohar
2016-02-12 12:53 ` Dave Young
2016-02-12 13:09 ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 20/22] ima: load policy using path Mimi Zohar
2016-02-07 19:59 ` Petko Manolov
2016-02-08 9:58 ` Dmitry Kasatkin
2016-02-08 10:35 ` Petko Manolov
2016-02-08 10:45 ` Dmitry Kasatkin
2016-02-08 21:12 ` Mimi Zohar
2016-02-09 7:47 ` Petko Manolov
2016-02-03 19:06 ` [PATCH v3 21/22] ima: measure and appraise the IMA policy itself Mimi Zohar
2016-02-07 20:01 ` Petko Manolov
2016-02-10 20:22 ` Dmitry Kasatkin
2016-02-10 23:15 ` Mimi Zohar
2016-02-03 19:06 ` [PATCH v3 22/22] ima: require signed IMA policy Mimi Zohar
2016-02-07 20:02 ` Petko Manolov
2016-02-10 20:24 ` Dmitry Kasatkin
2016-02-04 18:15 ` [PATCH v3 00/22] vfs: support for a common kernel file loader Kees Cook
2016-02-04 23:54 ` Mimi Zohar
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