From: David Miller <davem@davemloft.net>
To: jeremy@azazel.net
Cc: linux-x25@vger.kernel.org, netdev@vger.kernel.org,
syzbot+afb980676c836b4a0afa@syzkaller.appspotmail.com
Subject: Re: [PATCH net] lapb: fixed leak of control-blocks.
Date: Sun, 16 Jun 2019 20:44:57 -0700 (PDT) [thread overview]
Message-ID: <20190616.204457.1507896436828804410.davem@davemloft.net> (raw)
In-Reply-To: <20190616155437.25299-1-jeremy@azazel.net>
From: Jeremy Sowden <jeremy@azazel.net>
Date: Sun, 16 Jun 2019 16:54:37 +0100
> lapb_register calls lapb_create_cb, which initializes the control-
> block's ref-count to one, and __lapb_insert_cb, which increments it when
> adding the new block to the list of blocks.
>
> lapb_unregister calls __lapb_remove_cb, which decrements the ref-count
> when removing control-block from the list of blocks, and calls lapb_put
> itself to decrement the ref-count before returning.
>
> However, lapb_unregister also calls __lapb_devtostruct to look up the
> right control-block for the given net_device, and __lapb_devtostruct
> also bumps the ref-count, which means that when lapb_unregister returns
> the ref-count is still 1 and the control-block is leaked.
>
> Call lapb_put after __lapb_devtostruct to fix leak.
>
> Reported-by: syzbot+afb980676c836b4a0afa@syzkaller.appspotmail.com
> Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Applied and queued up for -stable.
prev parent reply other threads:[~2019-06-17 3:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-21 13:43 memory leak in lapb_register syzbot
2019-06-16 15:54 ` [PATCH net] lapb: fixed leak of control-blocks Jeremy Sowden
2019-06-17 3:44 ` David Miller [this message]
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