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/key.c b/security/keys/key.c
index 84d4eb5..1c2d43d 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -415,7 +415,7 @@
size_t datalen,
struct key *keyring,
struct key *authkey,
- struct keyring_list **_prealloc)
+ unsigned long *_prealloc)
{
int ret, awaken;
@@ -481,7 +481,7 @@
struct key *keyring,
struct key *authkey)
{
- struct keyring_list *prealloc;
+ unsigned long prealloc;
int ret;
if (keyring) {
@@ -526,7 +526,7 @@
struct key *keyring,
struct key *authkey)
{
- struct keyring_list *prealloc;
+ unsigned long prealloc;
struct timespec now;
int ret, awaken, link_ret = 0;
@@ -814,7 +814,7 @@
key_perm_t perm,
unsigned long flags)
{
- struct keyring_list *prealloc;
+ unsigned long prealloc;
const struct cred *cred = current_cred();
struct key_type *ktype;
struct key *keyring, *key = NULL;