cipso,calipso: resolve a number of problems with the DOI refcounts

commit ad5d07f4a9cd671233ae20983848874731102c08 upstream.

The current CIPSO and CALIPSO refcounting scheme for the DOI
definitions is a bit flawed in that we:

1. Don't correctly match gets/puts in netlbl_cipsov4_list().
2. Decrement the refcount on each attempt to remove the DOI from the
   DOI list, only removing it from the list once the refcount drops
   to zero.

This patch fixes these problems by adding the missing "puts" to
netlbl_cipsov4_list() and introduces a more conventional, i.e.
not-buggy, refcounting mechanism to the DOI definitions.  Upon the
addition of a DOI to the DOI list, it is initialized with a refcount
of one, removing a DOI from the list removes it from the list and
drops the refcount by one; "gets" and "puts" behave as expected with
respect to refcounts, increasing and decreasing the DOI's refcount by
one.

Fixes: b1edeb1023 ("netlabel: Replace protocol/NetLabel linking with refrerence counts")
Fixes: d7cce01504 ("netlabel: Add support for removing a CALIPSO DOI.")
Reported-by: syzbot+9ec037722d2603a9f52e@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paul Moore
2021-03-04 16:29:51 -05:00
committed by Greg Kroah-Hartman
parent e03ed1190d
commit 85178d76fe
3 changed files with 9 additions and 19 deletions

View File

@@ -575,6 +575,7 @@ list_start:
break;
}
cipso_v4_doi_putdef(doi_def);
rcu_read_unlock();
genlmsg_end(ans_skb, data);
@@ -583,12 +584,14 @@ list_start:
list_retry:
/* XXX - this limit is a guesstimate */
if (nlsze_mult < 4) {
cipso_v4_doi_putdef(doi_def);
rcu_read_unlock();
kfree_skb(ans_skb);
nlsze_mult *= 2;
goto list_start;
}
list_failure_lock:
cipso_v4_doi_putdef(doi_def);
rcu_read_unlock();
list_failure:
kfree_skb(ans_skb);