KEYS: Fix __key_link_end() quota fixup on error
Fix __key_link_end()'s attempt to fix up the quota if an error occurs.
There are two erroneous cases: Firstly, we always decrease the quota if
the preallocated replacement keyring needs cleaning up, irrespective of
whether or not we should (we may have replaced a pointer rather than
adding another pointer).
Secondly, we never clean up the quota if we added a pointer without the
keyring storage being extended (we allocate multiple pointers at a time,
even if we're not going to use them all immediately).
We handle this by setting the bottom bit of the preallocation pointer in
__key_link_begin() to indicate that the quota needs fixing up, which is
then passed to __key_link() (which clears the whole thing) and
__key_link_end().
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/keys/internal.h b/security/keys/internal.h
index edfa50d..a52aa7c 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -87,13 +87,13 @@
extern int __key_link_begin(struct key *keyring,
const struct key_type *type,
const char *description,
- struct keyring_list **_prealloc);
+ unsigned long *_prealloc);
extern int __key_link_check_live_key(struct key *keyring, struct key *key);
extern void __key_link(struct key *keyring, struct key *key,
- struct keyring_list **_prealloc);
+ unsigned long *_prealloc);
extern void __key_link_end(struct key *keyring,
struct key_type *type,
- struct keyring_list *prealloc);
+ unsigned long prealloc);
extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
const struct key_type *type,