From: jouni.hogander@unikie•com (Jouni Högander)
To: David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org, lukas.bulwahn@gmail•com
Subject: Re: [PATCH] net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject
Date: Wed, 20 Nov 2019 08:59:26 +0200 [thread overview]
Message-ID: <87wobvqbht.fsf@unikie.com> (raw)
In-Reply-To: <20191119.171333.624799505921966746.davem@davemloft.net> (David Miller's message of "Tue, 19 Nov 2019 17:13:33 -0800 (PST)")
David Miller <davem@davemloft•net> writes:
> From: jouni.hogander@unikie•com
> Date: Tue, 19 Nov 2019 11:51:21 +0200
>
>> kobject_init_and_add takes reference even when it fails.
>
> I see this in the comment above kobject_init_and_add() but not in the
> code.
>
> Where does the implementation of kobject_init_and_add() actually take
> such a reference?
kobject_init_and_add -> kobject_init -> kobject_init_internal -> kref_init
kref_init initializes ref_count as 1.
>
> Did you discover this by code inspection, or by an actual bug that was
> triggered? If by an actual bug, please provide the OOPS and/or checker
> trace that indicated a leak was happening here.
Originally found it via memory leak identified by Syzkaller. I will
submit new one with memleak dump.
>
> I don't see anything actually wrong here because kobject_init_and_add()
> doesn't actually seem to do what it's comment suggests...
See the code path above.
BR,
Jouni Högander
next prev parent reply other threads:[~2019-11-20 6:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 9:51 [PATCH] net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject jouni.hogander
2019-11-20 1:13 ` David Miller
2019-11-20 6:59 ` Jouni Högander [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-11-20 7:08 jouni.hogander
2019-11-20 20:10 ` David Miller
2019-11-21 3:12 ` Eric Dumazet
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