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-rw-r--r--security/integrity/ima/ima_main.c138
1 files changed, 63 insertions, 75 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index dba965de90d3..5127afcc4b89 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -61,7 +61,8 @@ static void ima_rdwr_violation_check(struct file *file)
fmode_t mode = file->f_mode;
int must_measure;
bool send_tomtou = false, send_writers = false;
- unsigned char *pathname = NULL, *pathbuf = NULL;
+ char *pathbuf = NULL;
+ const char *pathname;
if (!S_ISREG(inode->i_mode) || !ima_initialized)
return;
@@ -86,22 +87,15 @@ out:
if (!send_tomtou && !send_writers)
return;
- /* We will allow 11 spaces for ' (deleted)' to be appended */
- pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
- if (pathbuf) {
- pathname = d_path(&file->f_path, pathbuf, PATH_MAX + 11);
- if (IS_ERR(pathname))
- pathname = NULL;
- else if (strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
- pathname = NULL;
- }
+ pathname = ima_d_path(&file->f_path, &pathbuf);
+ if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
+ pathname = dentry->d_name.name;
+
if (send_tomtou)
- ima_add_violation(inode,
- !pathname ? dentry->d_name.name : pathname,
+ ima_add_violation(inode, pathname,
"invalid_pcr", "ToMToU");
if (send_writers)
- ima_add_violation(inode,
- !pathname ? dentry->d_name.name : pathname,
+ ima_add_violation(inode, pathname,
"invalid_pcr", "open_writers");
kfree(pathbuf);
}
@@ -145,25 +139,31 @@ void ima_file_free(struct file *file)
ima_check_last_writer(iint, inode, file);
}
-static int process_measurement(struct file *file, const unsigned char *filename,
+static int process_measurement(struct file *file, const char *filename,
int mask, int function)
{
struct inode *inode = file->f_dentry->d_inode;
struct integrity_iint_cache *iint;
- unsigned char *pathname = NULL, *pathbuf = NULL;
- int rc = -ENOMEM, action, must_appraise;
+ char *pathbuf = NULL;
+ const char *pathname = NULL;
+ int rc = -ENOMEM, action, must_appraise, _func;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
- /* Determine if in appraise/audit/measurement policy,
- * returns IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT bitmask. */
+ /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
+ * bitmask based on the appraise/audit/measurement policy.
+ * Included is the appraise submask.
+ */
action = ima_get_action(inode, mask, function);
if (!action)
return 0;
must_appraise = action & IMA_APPRAISE;
+ /* Is the appraise rule hook specific? */
+ _func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function;
+
mutex_lock(&inode->i_mutex);
iint = integrity_inode_get(inode);
@@ -171,44 +171,45 @@ static int process_measurement(struct file *file, const unsigned char *filename,
goto out;
/* Determine if already appraised/measured based on bitmask
- * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED,
- * IMA_AUDIT, IMA_AUDITED) */
+ * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
+ * IMA_AUDIT, IMA_AUDITED)
+ */
iint->flags |= action;
+ action &= IMA_DO_MASK;
action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
/* Nothing to do, just return existing appraised status */
if (!action) {
- if (iint->flags & IMA_APPRAISED)
- rc = iint->ima_status;
- goto out;
+ if (must_appraise)
+ rc = ima_get_cache_status(iint, _func);
+ goto out_digsig;
}
rc = ima_collect_measurement(iint, file);
if (rc != 0)
- goto out;
+ goto out_digsig;
+
+ if (function != BPRM_CHECK)
+ pathname = ima_d_path(&file->f_path, &pathbuf);
+
+ if (!pathname)
+ pathname = filename;
- if (function != BPRM_CHECK) {
- /* We will allow 11 spaces for ' (deleted)' to be appended */
- pathbuf = kmalloc(PATH_MAX + 11, GFP_KERNEL);
- if (pathbuf) {
- pathname =
- d_path(&file->f_path, pathbuf, PATH_MAX + 11);
- if (IS_ERR(pathname))
- pathname = NULL;
- }
- }
if (action & IMA_MEASURE)
- ima_store_measurement(iint, file,
- !pathname ? filename : pathname);
- if (action & IMA_APPRAISE)
- rc = ima_appraise_measurement(iint, file,
- !pathname ? filename : pathname);
+ ima_store_measurement(iint, file, pathname);
+ if (action & IMA_APPRAISE_SUBMASK)
+ rc = ima_appraise_measurement(_func, iint, file, pathname);
if (action & IMA_AUDIT)
- ima_audit_measurement(iint, !pathname ? filename : pathname);
+ ima_audit_measurement(iint, pathname);
kfree(pathbuf);
+out_digsig:
+ if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
+ rc = -EACCES;
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 +220,15 @@ out:
* 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, MMAP_CHECK);
+ return 0;
}
/**
@@ -244,18 +241,15 @@ 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 +259,15 @@ 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);
@@ -286,23 +277,20 @@ 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 = 0;
-
if (!file) {
- if (ima_appraise & IMA_APPRAISE_MODULES) {
#ifndef CONFIG_MODULE_SIG_FORCE
- rc = -EACCES; /* INTEGRITY_UNKNOWN */
+ if (ima_appraise & IMA_APPRAISE_MODULES)
+ return -EACCES; /* INTEGRITY_UNKNOWN */
#endif
- }
- } else
- rc = process_measurement(file, file->f_dentry->d_name.name,
- MAY_EXEC, MODULE_CHECK);
- return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
+ return 0; /* We rely on module signature checking */
+ }
+ return process_measurement(file, file->f_dentry->d_name.name,
+ MAY_EXEC, MODULE_CHECK);
}
static int __init init_ima(void)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 17:41:55 +0100