return found;
}
-/* ima_read_write_check - reflect possible reading/writing errors in the PCR.
- *
- * When opening a file for read, if the file is already open for write,
- * the file could change, resulting in a file measurement error.
- *
- * Opening a file for write, if the file is already open for read, results
- * in a time of measure, time of use (ToMToU) error.
- *
- * In either case invalidate the PCR.
- */
-enum iint_pcr_error { TOMTOU, OPEN_WRITERS };
-static void ima_read_write_check(enum iint_pcr_error error,
- struct ima_iint_cache *iint,
- struct inode *inode,
- const unsigned char *filename)
-{
- switch (error) {
- case TOMTOU:
- if (iint->readcount > 0)
- ima_add_violation(inode, filename, "invalid_pcr",
- "ToMToU");
- break;
- case OPEN_WRITERS:
- if (iint->writecount > 0)
- ima_add_violation(inode, filename, "invalid_pcr",
- "open_writers");
- break;
- }
-}
-
/*
* Update the counts given an fmode_t
*/
static void ima_inc_counts(struct ima_iint_cache *iint, fmode_t mode)
{
- BUG_ON(!mutex_is_locked(&iint->mutex));
+ assert_spin_locked(&iint->inode->i_lock);
- iint->opencount++;
if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount++;
if (mode & FMODE_WRITE)
fmode_t mode = file->f_mode;
struct ima_iint_cache *iint;
int rc;
+ bool send_tomtou = false, send_writers = false;
- if (!ima_initialized || !S_ISREG(inode->i_mode))
+ if (!iint_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
+ spin_lock(&inode->i_lock);
+
+ if (!ima_initialized)
+ goto out;
+
rc = ima_must_measure(iint, inode, MAY_READ, FILE_CHECK);
if (rc < 0)
goto out;
if (mode & FMODE_WRITE) {
- ima_read_write_check(TOMTOU, iint, inode, dentry->d_name.name);
+ if (iint->readcount)
+ send_tomtou = true;
goto out;
}
- ima_read_write_check(OPEN_WRITERS, iint, inode, dentry->d_name.name);
+
+ if (atomic_read(&inode->i_writecount) > 0)
+ send_writers = true;
out:
ima_inc_counts(iint, file->f_mode);
+ spin_unlock(&inode->i_lock);
mutex_unlock(&iint->mutex);
-
kref_put(&iint->refcount, iint_free);
+
+ if (send_tomtou)
+ ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
+ "ToMToU");
+ if (send_writers)
+ ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
+ "open_writers");
}
/*
struct file *file)
{
mode_t mode = file->f_mode;
+ bool dump = false;
+
BUG_ON(!mutex_is_locked(&iint->mutex));
+ assert_spin_locked(&inode->i_lock);
- iint->opencount--;
- if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+ if ((mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
+ if (unlikely(iint->readcount == 0))
+ dump = true;
iint->readcount--;
+ }
if (mode & FMODE_WRITE) {
+ if (unlikely(iint->writecount == 0))
+ dump = true;
iint->writecount--;
if (iint->writecount == 0) {
if (iint->version != inode->i_version)
}
}
- if (((iint->opencount < 0) ||
- (iint->readcount < 0) ||
- (iint->writecount < 0)) &&
- !ima_limit_imbalance(file)) {
- printk(KERN_INFO "%s: open/free imbalance (r:%ld w:%ld o:%ld)\n",
- __func__, iint->readcount, iint->writecount,
- iint->opencount);
+ if (dump && !ima_limit_imbalance(file)) {
+ printk(KERN_INFO "%s: open/free imbalance (r:%u w:%u)\n",
+ __func__, iint->readcount, iint->writecount);
dump_stack();
}
}
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
- if (!ima_initialized || !S_ISREG(inode->i_mode))
+ if (!iint_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
+ spin_lock(&inode->i_lock);
+
ima_dec_counts(iint, inode, file);
+
+ spin_unlock(&inode->i_lock);
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
}
{
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
- int rc;
+ int rc = 0;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;