audit: replace getname()/putname() hacks with reference counters
In order to ensure that filenames are not released before the audit
subsystem is done with the strings there are a number of hacks built
into the fs and audit subsystems around getname() and putname(). To
say these hacks are "ugly" would be kind.
This patch removes the filename hackery in favor of a more
conventional reference count based approach. The diffstat below tells
most of the story; lots of audit/fs specific code is replaced with a
traditional reference count based approach that is easily understood,
even by those not familiar with the audit and/or fs subsystems.
CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f90c028..b49842f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2080,6 +2080,7 @@
const char *name; /* pointer to actual string */
const __user char *uptr; /* original userland pointer */
struct audit_names *aname;
+ int refcnt;
bool separate; /* should "name" be freed? */
};
@@ -2101,6 +2102,7 @@
extern struct filename *getname_flags(const char __user *, int, int *);
extern struct filename *getname(const char __user *);
extern struct filename *getname_kernel(const char *);
+extern void putname(struct filename *name);
enum {
FILE_CREATED = 1,
@@ -2121,15 +2123,8 @@
extern struct kmem_cache *names_cachep;
-extern void final_putname(struct filename *name);
-
#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL)
#define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
-#ifndef CONFIG_AUDITSYSCALL
-#define putname(name) final_putname(name)
-#else
-extern void putname(struct filename *name);
-#endif
#ifdef CONFIG_BLOCK
extern int register_blkdev(unsigned int, const char *);