Commit 750943a3 authored by Dmitry Kasatkin's avatar Dmitry Kasatkin Committed by Mimi Zohar

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: default avatarDmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
parent def3e8b9
...@@ -208,7 +208,9 @@ static int process_measurement(struct file *file, const unsigned char *filename, ...@@ -208,7 +208,9 @@ static int process_measurement(struct file *file, const unsigned char *filename,
kfree(pathbuf); kfree(pathbuf);
out: out:
mutex_unlock(&inode->i_mutex); 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, ...@@ -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() * Measure files being mmapped executable based on the ima_must_measure()
* policy decision. * policy decision.
* *
* Return 0 on success, an error code on failure. * On success return 0. On integrity appraisal error, assuming the file
* (Based on the results of appraise_measurement().) * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/ */
int ima_file_mmap(struct file *file, unsigned long prot) int ima_file_mmap(struct file *file, unsigned long prot)
{ {
int rc = 0; if (file && (prot & PROT_EXEC))
return process_measurement(file, file->f_dentry->d_name.name,
if (!file) MAY_EXEC, FILE_MMAP);
return 0; 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;
} }
/** /**
...@@ -244,18 +242,15 @@ int ima_file_mmap(struct file *file, unsigned long prot) ...@@ -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 * So we can be certain that what we verify and measure here is actually
* what is being executed. * what is being executed.
* *
* Return 0 on success, an error code on failure. * On success return 0. On integrity appraisal error, assuming the file
* (Based on the results of appraise_measurement().) * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/ */
int ima_bprm_check(struct linux_binprm *bprm) int ima_bprm_check(struct linux_binprm *bprm)
{ {
int rc; return process_measurement(bprm->file,
rc = process_measurement(bprm->file,
(strcmp(bprm->filename, bprm->interp) == 0) ? (strcmp(bprm->filename, bprm->interp) == 0) ?
bprm->filename : bprm->interp, bprm->filename : bprm->interp,
MAY_EXEC, BPRM_CHECK); MAY_EXEC, BPRM_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
} }
/** /**
...@@ -265,18 +260,15 @@ int ima_bprm_check(struct linux_binprm *bprm) ...@@ -265,18 +260,15 @@ int ima_bprm_check(struct linux_binprm *bprm)
* *
* Measure files based on the ima_must_measure() policy decision. * Measure files based on the ima_must_measure() policy decision.
* *
* Always return 0 and audit dentry_open failures. * On success return 0. On integrity appraisal error, assuming the file
* (Return code will be based upon measurement appraisal.) * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/ */
int ima_file_check(struct file *file, int mask) int ima_file_check(struct file *file, int mask)
{ {
int rc;
ima_rdwr_violation_check(file); 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), mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK); FILE_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
} }
EXPORT_SYMBOL_GPL(ima_file_check); EXPORT_SYMBOL_GPL(ima_file_check);
...@@ -286,19 +278,15 @@ EXPORT_SYMBOL_GPL(ima_file_check); ...@@ -286,19 +278,15 @@ EXPORT_SYMBOL_GPL(ima_file_check);
* *
* Measure/appraise kernel modules based on policy. * Measure/appraise kernel modules based on policy.
* *
* Always return 0 and audit dentry_open failures. * On success return 0. On integrity appraisal error, assuming the file
* Return code is based upon measurement appraisal. * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/ */
int ima_module_check(struct file *file) int ima_module_check(struct file *file)
{ {
int rc;
if (!file) if (!file)
rc = INTEGRITY_UNKNOWN; return -EACCES; /* INTEGRITY_UNKNOWN */
else return process_measurement(file, file->f_dentry->d_name.name,
rc = process_measurement(file, file->f_dentry->d_name.name, MAY_EXEC, MODULE_CHECK);
MAY_EXEC, MODULE_CHECK);
return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
} }
static int __init init_ima(void) static int __init init_ima(void)
......
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