> On Mar 30, 2023, at 2:49 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Thu, 2023-03-30 at 18:31 +0000, Chuck Lever III wrote:
>> Hi Jeff-
>>
>>> On Mar 30, 2023, at 2:24 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>>>
>>> While the unix_gid object is rcu-freed, the group_info list that it
>>> contains is not. Ensure that we only put the group list reference once
>>> we are really freeing the unix_gid object.
>>>
>>> Reported-by: Zhi Li <yieli@xxxxxxxxxx>
>>
>> Should we also add
>>
>> Fixes: fd5d2f78261b ("SUNRPC: Make server side AUTH_UNIX use lockless lookups") ?
>>
>>
>
> Sure. That does look like when that particular bug crept in.
>
>>> Link: https://bugzilla.redhat.com/show_bug.cgi?id=2183056
>>
>> This bug isn't publicly accessible, fwiw.
>>
>
> Thanks. It should be now.
OK, applied to nfsd-fixes!
>>> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
>>> ---
>>> net/sunrpc/svcauth_unix.c | 17 +++++++++++++----
>>> 1 file changed, 13 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
>>> index 50e2eb579194..4485088ce27b 100644
>>> --- a/net/sunrpc/svcauth_unix.c
>>> +++ b/net/sunrpc/svcauth_unix.c
>>> @@ -416,14 +416,23 @@ static int unix_gid_hash(kuid_t uid)
>>> return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS);
>>> }
>>>
>>> -static void unix_gid_put(struct kref *kref)
>>> +static void unix_gid_free(struct rcu_head *rcu)
>>> {
>>> - struct cache_head *item = container_of(kref, struct cache_head, ref);
>>> - struct unix_gid *ug = container_of(item, struct unix_gid, h);
>>> + struct unix_gid *ug = container_of(rcu, struct unix_gid, rcu);
>>> + struct cache_head *item = &ug->h;
>>> +
>>> if (test_bit(CACHE_VALID, &item->flags) &&
>>> !test_bit(CACHE_NEGATIVE, &item->flags))
>>> put_group_info(ug->gi);
>>> - kfree_rcu(ug, rcu);
>>> + kfree(ug);
>>> +}
>>> +
>>> +static void unix_gid_put(struct kref *kref)
>>> +{
>>> + struct cache_head *item = container_of(kref, struct cache_head, ref);
>>> + struct unix_gid *ug = container_of(item, struct unix_gid, h);
>>> +
>>> + call_rcu(&ug->rcu, unix_gid_free);
>>> }
>>>
>>> static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
>>> --
>>> 2.39.2
>>>
>>
>> --
>> Chuck Lever
>>
>>
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
--
Chuck Lever
