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module: replace copy_module_from_fd with kernel version

Telusuri Sumber 
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>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Mimi Zohar
2015-12-30 07:35:30 -05:00
orang tua b844f0ecbc
melakukan a1db742094
7 mengubah file dengan 22 tambahan dan 112 penghapusan
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35
security/integrity/ima/ima_main.c
Melihat File

@@ -315,28 +315,6 @@ 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
@@ -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);
}