Replace the fw_read_file_contents with kernel_file_read_from_path().
Although none of the upstreamed LSMs define a kernel_fw_from_file hook,
IMA is called by the security function to prevent unsigned firmware from
being loaded and to measure/appraise signed firmware, based on policy.
Instead of reading the firmware twice, once for measuring/appraising the
firmware and again for reading the firmware contents into memory, the
kernel_post_read_file() security hook calculates the file hash based on
the in memory file buffer. The firmware is read once.
This patch removes the LSM kernel_fw_from_file() hook and security call.
Changelog v4+:
- revert dropped buf->size assignment - reported by Sergey Senozhatsky
v3:
- remove kernel_fw_from_file hook
- use kernel_file_read_from_path() - requested by Luis
v2:
- reordered and squashed firmware patches
- fix MAX firmware size (Kees Cook)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/list.h>
+#include <linux/fs.h>
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
-static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
-{
- int size;
- char *buf;
- int rc;
-
- if (!S_ISREG(file_inode(file)->i_mode))
- return -EINVAL;
- size = i_size_read(file_inode(file));
- if (size <= 0)
- return -EINVAL;
- buf = vmalloc(size);
- if (!buf)
- return -ENOMEM;
- rc = kernel_read(file, 0, buf, size);
- if (rc != size) {
- if (rc > 0)
- rc = -EIO;
- goto fail;
- }
- rc = security_kernel_fw_from_file(file, buf, size);
- if (rc)
- goto fail;
- fw_buf->data = buf;
- fw_buf->size = size;
- return 0;
-fail:
- vfree(buf);
- return rc;
-}
-
static void fw_finish_direct_load(struct device *device,
struct firmware_buf *buf)
{
static int fw_get_filesystem_firmware(struct device *device,
struct firmware_buf *buf)
{
+ loff_t size;
int i, len;
int rc = -ENOENT;
char *path;
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
- struct file *file;
-
/* skip the unset customized path */
if (!fw_path[i][0])
continue;
break;
}
- file = filp_open(path, O_RDONLY, 0);
- if (IS_ERR(file))
- continue;
- rc = fw_read_file_contents(file, buf);
- fput(file);
+ buf->size = 0;
+ rc = kernel_read_file_from_path(path, &buf->data, &size,
+ INT_MAX, READING_FIRMWARE);
if (rc) {
dev_warn(device, "loading %s failed with error %d\n",
path, rc);
continue;
}
- dev_dbg(device, "direct-loading %s\n",
- buf->fw_id);
+ dev_dbg(device, "direct-loading %s\n", buf->fw_id);
+ buf->size = size;
fw_finish_direct_load(device, buf);
break;
}
dev_err(dev, "%s: map pages failed\n",
__func__);
else
- rc = security_kernel_fw_from_file(NULL,
- fw_buf->data, fw_buf->size);
+ rc = security_kernel_post_read_file(NULL,
+ fw_buf->data, fw_buf->size,
+ READING_FIRMWARE);
/*
* Same logic as fw_load_abort, only the DONE bit
extern int do_pipe_flags(int *, int);
enum kernel_read_file_id {
+ READING_FIRMWARE = 1,
READING_MAX_ID
};
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_fw_from_file(struct file *file, char *buf, size_t size);
extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id);
return 0;
}
-static inline int ima_fw_from_file(struct file *file, char *buf, size_t size)
-{
- return 0;
-}
-
static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum kernel_read_file_id id)
{
* @inode points to the inode to use as a reference.
* The current task must be the one that nominated @inode.
* Return 0 if successful.
- * @kernel_fw_from_file:
- * Load firmware from userspace (not called for built-in firmware).
- * @file contains the file structure pointing to the file containing
- * the firmware to load. This argument will be NULL if the firmware
- * was loaded via the uevent-triggered blob-based interface exposed
- * by CONFIG_FW_LOADER_USER_HELPER.
- * @buf pointer to buffer containing firmware contents.
- * @size length of the firmware contents.
- * Return 0 if permission is granted.
* @kernel_module_request:
* Ability to trigger the kernel to automatically upcall to userspace for
* userspace to load a kernel module with the given name.
void (*cred_transfer)(struct cred *new, const struct cred *old);
int (*kernel_act_as)(struct cred *new, u32 secid);
int (*kernel_create_files_as)(struct cred *new, struct inode *inode);
- int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size);
int (*kernel_module_request)(char *kmod_name);
int (*kernel_module_from_file)(struct file *file);
int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size,
struct list_head cred_transfer;
struct list_head kernel_act_as;
struct list_head kernel_create_files_as;
- struct list_head kernel_fw_from_file;
struct list_head kernel_post_read_file;
struct list_head kernel_module_request;
struct list_head kernel_module_from_file;
void security_transfer_creds(struct cred *new, const struct cred *old);
int security_kernel_act_as(struct cred *new, u32 secid);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
-int security_kernel_fw_from_file(struct file *file, char *buf, size_t size);
int security_kernel_module_request(char *kmod_name);
int security_kernel_module_from_file(struct file *file);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
return 0;
}
-static inline int security_kernel_fw_from_file(struct file *file,
- char *buf, size_t size)
-{
- return 0;
-}
-
static inline int security_kernel_module_request(char *kmod_name)
{
return 0;
return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0);
}
-int ima_fw_from_file(struct file *file, char *buf, size_t size)
-{
- if (!file) {
- if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
- (ima_appraise & IMA_APPRAISE_ENFORCE))
- return -EACCES; /* INTEGRITY_UNKNOWN */
- return 0;
- }
- return process_measurement(file, NULL, 0, MAY_EXEC, FIRMWARE_CHECK, 0);
-}
-
/**
* ima_post_read_file - in memory collect/appraise/audit measurement
* @file: pointer to the file to be measured/appraised/audit
{
enum ima_hooks func = FILE_CHECK;
+ if (!file && read_id == READING_FIRMWARE) {
+ if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
+ (ima_appraise & IMA_APPRAISE_ENFORCE))
+ return -EACCES; /* INTEGRITY_UNKNOWN */
+ return 0;
+ }
+
if (!file || !buf || size == 0) { /* should never happen */
if (ima_appraise & IMA_APPRAISE_ENFORCE)
return -EACCES;
return 0;
}
+ if (read_id == READING_FIRMWARE)
+ func = FIRMWARE_CHECK;
+
return process_measurement(file, buf, size, MAY_READ, func, 0);
}
return call_int_hook(kernel_create_files_as, 0, new, inode);
}
-int security_kernel_fw_from_file(struct file *file, char *buf, size_t size)
-{
- int ret;
-
- ret = call_int_hook(kernel_fw_from_file, 0, file, buf, size);
- if (ret)
- return ret;
- return ima_fw_from_file(file, buf, size);
-}
-EXPORT_SYMBOL_GPL(security_kernel_fw_from_file);
-
int security_kernel_module_request(char *kmod_name)
{
return call_int_hook(kernel_module_request, 0, kmod_name);
LIST_HEAD_INIT(security_hook_heads.kernel_act_as),
.kernel_create_files_as =
LIST_HEAD_INIT(security_hook_heads.kernel_create_files_as),
- .kernel_fw_from_file =
- LIST_HEAD_INIT(security_hook_heads.kernel_fw_from_file),
.kernel_module_request =
LIST_HEAD_INIT(security_hook_heads.kernel_module_request),
.kernel_module_from_file =
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff