audit: overhaul __audit_inode_child to accomodate retrying

In order to accomodate retrying path-based syscalls, we need to add a
new "type" argument to audit_inode_child. This will tell us whether
we're looking for a child entry that represents a create or a delete.

If we find a parent, don't automatically assume that we need to create a
new entry. Instead, use the information we have to try to find an
existing entry first. Update it if one is found and create a new one if
not.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Jeff Layton 2012-10-10 15:25:25 -04:00 committed by Al Viro
parent e3d6b07b8b
commit 4fa6b5ecbf
5 changed files with 47 additions and 38 deletions

View File

@ -638,7 +638,7 @@ static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
return -ENOENT;
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(dir, victim);
audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)

View File

@ -2176,7 +2176,7 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir)
return -ENOENT;
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(dir, victim);
audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)

View File

@ -457,6 +457,8 @@ extern int audit_classify_arch(int arch);
#define AUDIT_TYPE_UNKNOWN 0 /* we don't know yet */
#define AUDIT_TYPE_NORMAL 1 /* a "normal" audit record */
#define AUDIT_TYPE_PARENT 2 /* a parent audit record */
#define AUDIT_TYPE_CHILD_DELETE 3 /* a child being deleted */
#define AUDIT_TYPE_CHILD_CREATE 4 /* a child being created */
#ifdef CONFIG_AUDITSYSCALL
/* These are defined in auditsc.c */
@ -472,7 +474,8 @@ extern void audit_putname(const char *name);
extern void __audit_inode(const char *name, const struct dentry *dentry,
unsigned int parent);
extern void __audit_inode_child(const struct inode *parent,
const struct dentry *dentry);
const struct dentry *dentry,
const unsigned char type);
extern void __audit_seccomp(unsigned long syscall, long signr, int code);
extern void __audit_ptrace(struct task_struct *t);
@ -513,9 +516,10 @@ static inline void audit_inode(const char *name, const struct dentry *dentry,
__audit_inode(name, dentry, parent);
}
static inline void audit_inode_child(const struct inode *parent,
const struct dentry *dentry) {
const struct dentry *dentry,
const unsigned char type) {
if (unlikely(!audit_dummy_context()))
__audit_inode_child(parent, dentry);
__audit_inode_child(parent, dentry, type);
}
void audit_core_dumps(long signr);
@ -667,13 +671,15 @@ static inline void __audit_inode(const char *name, const struct dentry *dentry,
unsigned int parent)
{ }
static inline void __audit_inode_child(const struct inode *parent,
const struct dentry *dentry)
const struct dentry *dentry,
const unsigned char type)
{ }
static inline void audit_inode(const char *name, const struct dentry *dentry,
unsigned int parent)
{ }
static inline void audit_inode_child(const struct inode *parent,
const struct dentry *dentry)
const struct dentry *dentry,
const unsigned char type)
{ }
static inline void audit_core_dumps(long signr)
{ }

View File

@ -109,7 +109,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
if (source)
fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
audit_inode_child(new_dir, moved);
audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE);
}
/*
@ -155,7 +155,7 @@ static inline void fsnotify_inoderemove(struct inode *inode)
*/
static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
{
audit_inode_child(inode, dentry);
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
}
@ -168,7 +168,7 @@ static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
{
fsnotify_link_count(inode);
audit_inode_child(dir, new_dentry);
audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
}
@ -181,7 +181,7 @@ static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
__u32 mask = (FS_CREATE | FS_ISDIR);
struct inode *d_inode = dentry->d_inode;
audit_inode_child(inode, dentry);
audit_inode_child(inode, dentry, AUDIT_TYPE_CHILD_CREATE);
fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
}

View File

@ -2189,6 +2189,7 @@ void __audit_inode(const char *name, const struct dentry *dentry,
* __audit_inode_child - collect inode info for created/removed objects
* @parent: inode of dentry parent
* @dentry: dentry being audited
* @type: AUDIT_TYPE_* value that we're looking for
*
* For syscalls that create or remove filesystem objects, audit_inode
* can only collect information for the filesystem object's parent.
@ -2199,13 +2200,13 @@ void __audit_inode(const char *name, const struct dentry *dentry,
* unsuccessful attempts.
*/
void __audit_inode_child(const struct inode *parent,
const struct dentry *dentry)
const struct dentry *dentry,
const unsigned char type)
{
struct audit_context *context = current->audit_context;
const char *found_parent = NULL, *found_child = NULL;
const struct inode *inode = dentry->d_inode;
const char *dname = dentry->d_name.name;
struct audit_names *n;
struct audit_names *n, *found_parent = NULL, *found_child = NULL;
if (!context->in_syscall)
return;
@ -2213,63 +2214,65 @@ void __audit_inode_child(const struct inode *parent,
if (inode)
handle_one(inode);
/* parent is more likely, look for it first */
/* look for a parent entry first */
list_for_each_entry(n, &context->names_list, list) {
if (!n->name)
if (!n->name || n->type != AUDIT_TYPE_PARENT)
continue;
if (n->ino == parent->i_ino &&
!audit_compare_dname_path(dname, n->name, n->name_len)) {
found_parent = n->name;
goto add_names;
found_parent = n;
break;
}
}
/* no matching parent, look for matching child */
/* is there a matching child entry? */
list_for_each_entry(n, &context->names_list, list) {
if (!n->name)
/* can only match entries that have a name */
if (!n->name || n->type != type)
continue;
/* if we found a parent, make sure this one is a child of it */
if (found_parent && (n->name != found_parent->name))
continue;
/* strcmp() is the more likely scenario */
if (!strcmp(dname, n->name) ||
!audit_compare_dname_path(dname, n->name,
found_parent ?
found_parent->name_len :
AUDIT_NAME_FULL)) {
if (inode)
audit_copy_inode(n, dentry, inode);
else
n->ino = (unsigned long)-1;
n->type = AUDIT_TYPE_NORMAL;
found_child = n->name;
goto add_names;
found_child = n;
break;
}
}
add_names:
if (!found_parent) {
n = audit_alloc_name(context, AUDIT_TYPE_NORMAL);
/* create a new, "anonymous" parent record */
n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
if (!n)
return;
audit_copy_inode(n, NULL, parent);
}
if (!found_child) {
n = audit_alloc_name(context, AUDIT_TYPE_NORMAL);
if (!n)
found_child = audit_alloc_name(context, type);
if (!found_child)
return;
/* 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) {
n->name = found_parent;
n->name_len = AUDIT_NAME_FULL;
found_child->name = found_parent->name;
found_child->name_len = AUDIT_NAME_FULL;
/* don't call __putname() */
n->name_put = false;
found_child->name_put = false;
}
if (inode)
audit_copy_inode(n, dentry, inode);
}
if (inode)
audit_copy_inode(found_child, dentry, inode);
else
found_child->ino = (unsigned long)-1;
}
EXPORT_SYMBOL_GPL(__audit_inode_child);