Commit 5712e88f authored by Amy Griffis's avatar Amy Griffis Committed by Al Viro
Browse files

[PATCH] match audit name data



Make more effort to detect previously collected names, so we don't log
multiple PATH records for a single filesystem object. Add
audit_inc_name_count() to reduce duplicate code.
Signed-off-by: default avatarAmy Griffis <amy.griffis@hp.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 4fc03b9b
......@@ -78,11 +78,6 @@ extern int audit_enabled;
* for saving names from getname(). */
#define AUDIT_NAMES 20
/* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
* audit_context from being used for nameless inodes from
* path_lookup. */
#define AUDIT_NAMES_RESERVED 7
/* Indicates that audit should log the full pathname. */
#define AUDIT_NAME_FULL -1
......@@ -1343,6 +1338,28 @@ void audit_putname(const char *name)
#endif
}
static int audit_inc_name_count(struct audit_context *context,
const struct inode *inode)
{
if (context->name_count >= AUDIT_NAMES) {
if (inode)
printk(KERN_DEBUG "name_count maxed, losing inode data: "
"dev=%02x:%02x, inode=%lu",
MAJOR(inode->i_sb->s_dev),
MINOR(inode->i_sb->s_dev),
inode->i_ino);
else
printk(KERN_DEBUG "name_count maxed, losing inode data");
return 1;
}
context->name_count++;
#if AUDIT_DEBUG
context->ino_count++;
#endif
return 0;
}
/* Copy inode data into an audit_names. */
static void audit_copy_inode(struct audit_names *name, const struct inode *inode)
{
......@@ -1380,13 +1397,10 @@ void __audit_inode(const char *name, const struct inode *inode)
else {
/* FIXME: how much do we care about inodes that have no
* associated name? */
if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
if (audit_inc_name_count(context, inode))
return;
idx = context->name_count++;
idx = context->name_count - 1;
context->names[idx].name = NULL;
#if AUDIT_DEBUG
++context->ino_count;
#endif
}
audit_copy_inode(&context->names[idx], inode);
}
......@@ -1410,7 +1424,7 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
{
int idx;
struct audit_context *context = current->audit_context;
const char *found_name = NULL;
const char *found_parent = NULL, *found_child = NULL;
int dirlen = 0;
if (!context->in_syscall)
......@@ -1418,61 +1432,73 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
/* determine matching parent */
if (!dname)
goto update_context;
for (idx = 0; idx < context->name_count; idx++)
if (context->names[idx].ino == parent->i_ino) {
const char *name = context->names[idx].name;
goto add_names;
if (!name)
continue;
/* parent is more likely, look for it first */
for (idx = 0; idx < context->name_count; idx++) {
struct audit_names *n = &context->names[idx];
if (audit_compare_dname_path(dname, name, &dirlen) == 0) {
context->names[idx].name_len = dirlen;
found_name = name;
break;
}
if (!n->name)
continue;
if (n->ino == parent->i_ino &&
!audit_compare_dname_path(dname, n->name, &dirlen)) {
n->name_len = dirlen; /* update parent data in place */
found_parent = n->name;
goto add_names;
}
}
update_context:
idx = context->name_count;
if (context->name_count == AUDIT_NAMES) {
printk(KERN_DEBUG "name_count maxed and losing %s\n",
found_name ?: "(null)");
return;
/* no matching parent, look for matching child */
for (idx = 0; idx < context->name_count; idx++) {
struct audit_names *n = &context->names[idx];
if (!n->name)
continue;
/* strcmp() is the more likely scenario */
if (!strcmp(dname, n->name) ||
!audit_compare_dname_path(dname, n->name, &dirlen)) {
if (inode)
audit_copy_inode(n, inode);
else
n->ino = (unsigned long)-1;
found_child = n->name;
goto add_names;
}
}
context->name_count++;
#if AUDIT_DEBUG
context->ino_count++;
#endif
/* Re-use the name belonging to the slot for a matching parent directory.
* All names for this context are relinquished in audit_free_names() */
context->names[idx].name = found_name;
context->names[idx].name_len = AUDIT_NAME_FULL;
context->names[idx].name_put = 0; /* don't call __putname() */
if (!inode)
context->names[idx].ino = (unsigned long)-1;
else
audit_copy_inode(&context->names[idx], inode);
/* A parent was not found in audit_names, so copy the inode data for the
* provided parent. */
if (!found_name) {
idx = context->name_count;
if (context->name_count == AUDIT_NAMES) {
printk(KERN_DEBUG
"name_count maxed and losing parent inode data: dev=%02x:%02x, inode=%lu",
MAJOR(parent->i_sb->s_dev),
MINOR(parent->i_sb->s_dev),
parent->i_ino);
add_names:
if (!found_parent) {
if (audit_inc_name_count(context, parent))
return;
}
context->name_count++;
#if AUDIT_DEBUG
context->ino_count++;
#endif
idx = context->name_count - 1;
context->names[idx].name = NULL;
audit_copy_inode(&context->names[idx], parent);
}
if (!found_child) {
if (audit_inc_name_count(context, inode))
return;
idx = context->name_count - 1;
/* Re-use the name belonging to the slot for a matching parent
* directory. All names for this context are relinquished in
* audit_free_names() */
if (found_parent) {
context->names[idx].name = found_parent;
context->names[idx].name_len = AUDIT_NAME_FULL;
/* don't call __putname() */
context->names[idx].name_put = 0;
} else {
context->names[idx].name = NULL;
}
if (inode)
audit_copy_inode(&context->names[idx], inode);
else
context->names[idx].ino = (unsigned long)-1;
}
}
/**
......
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