ima: remove enforce checking duplication

Based on the IMA appraisal policy, files are appraised.  For those
files appraised, the IMA hooks return the integrity appraisal result,
assuming IMA-appraisal is in enforcing mode.  This patch combines
both of these criteria (in policy and enforcing file integrity),
removing the checking duplication.

Changelog v1:
- Update hook comments

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Dmitry Kasatkin 2012-09-27 15:57:10 +03:00 committed by Mimi Zohar
parent def3e8b9ee
commit 750943a307

View file

@ -208,7 +208,9 @@ static int process_measurement(struct file *file, const unsigned char *filename,
kfree(pathbuf);
out:
mutex_unlock(&inode->i_mutex);
return (rc && must_appraise) ? -EACCES : 0;
if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
return -EACCES;
return 0;
}
/**
@ -219,19 +221,15 @@ static int process_measurement(struct file *file, const unsigned char *filename,
* Measure files being mmapped executable based on the ima_must_measure()
* policy decision.
*
* Return 0 on success, an error code on failure.
* (Based on the results of appraise_measurement().)
* 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_file_mmap(struct file *file, unsigned long prot)
{
int rc = 0;
if (!file)
return 0;
if (prot & PROT_EXEC)
rc = process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, FILE_MMAP);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
if (file && (prot & PROT_EXEC))
return process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, FILE_MMAP);
return 0;
}
/**
@ -244,18 +242,15 @@ int ima_file_mmap(struct file *file, unsigned long prot)
* So we can be certain that what we verify and measure here is actually
* what is being executed.
*
* Return 0 on success, an error code on failure.
* (Based on the results of appraise_measurement().)
* 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_bprm_check(struct linux_binprm *bprm)
{
int rc;
rc = process_measurement(bprm->file,
return process_measurement(bprm->file,
(strcmp(bprm->filename, bprm->interp) == 0) ?
bprm->filename : bprm->interp,
MAY_EXEC, BPRM_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
/**
@ -265,18 +260,15 @@ int ima_bprm_check(struct linux_binprm *bprm)
*
* Measure files based on the ima_must_measure() policy decision.
*
* Always return 0 and audit dentry_open failures.
* (Return code will be based upon measurement appraisal.)
* 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_file_check(struct file *file, int mask)
{
int rc;
ima_rdwr_violation_check(file);
rc = process_measurement(file, file->f_dentry->d_name.name,
return process_measurement(file, file->f_dentry->d_name.name,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
EXPORT_SYMBOL_GPL(ima_file_check);
@ -286,19 +278,15 @@ EXPORT_SYMBOL_GPL(ima_file_check);
*
* Measure/appraise kernel modules based on policy.
*
* Always return 0 and audit dentry_open failures.
* Return code is based upon measurement appraisal.
* 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)
{
int rc;
if (!file)
rc = INTEGRITY_UNKNOWN;
else
rc = process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, MODULE_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
return -EACCES; /* INTEGRITY_UNKNOWN */
return process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, MODULE_CHECK);
}
static int __init init_ima(void)