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authorPaul Moore <paul@paul-moore.com>2021-03-05 00:29:51 +0300
committerDavid S. Miller <davem@davemloft.net>2021-03-05 02:26:57 +0300
commitad5d07f4a9cd671233ae20983848874731102c08 (patch)
tree3f3646f6f025a9f2f2701773053ad4fe378e207e /net/ipv4/cipso_ipv4.c
parent67eb211487f0c993d9f402d1c196ef159fd6a3b5 (diff)
downloadlinux-ad5d07f4a9cd671233ae20983848874731102c08.tar.xz
cipso,calipso: resolve a number of problems with the DOI refcounts
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: b1edeb102397 ("netlabel: Replace protocol/NetLabel linking with refrerence counts") Fixes: d7cce01504a0 ("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>
Diffstat (limited to 'net/ipv4/cipso_ipv4.c')
-rw-r--r--net/ipv4/cipso_ipv4.c11
1 files changed, 1 insertions, 10 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 471d33a0d095..be09c7669a79 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -519,16 +519,10 @@ int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
ret_val = -ENOENT;
goto doi_remove_return;
}
- if (!refcount_dec_and_test(&doi_def->refcount)) {
- spin_unlock(&cipso_v4_doi_list_lock);
- ret_val = -EBUSY;
- goto doi_remove_return;
- }
list_del_rcu(&doi_def->list);
spin_unlock(&cipso_v4_doi_list_lock);
- cipso_v4_cache_invalidate();
- call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
+ cipso_v4_doi_putdef(doi_def);
ret_val = 0;
doi_remove_return:
@@ -585,9 +579,6 @@ void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
if (!refcount_dec_and_test(&doi_def->refcount))
return;
- spin_lock(&cipso_v4_doi_list_lock);
- list_del_rcu(&doi_def->list);
- spin_unlock(&cipso_v4_doi_list_lock);
cipso_v4_cache_invalidate();
call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);