Re: [PATCH net] dibs: fix use-after-free of dmb_node in loopback attach/detach/unregister

Hidayathulla Khan I <[email protected]> Wed, 29 Jul 2026 18:20:00 +0530
Newsgroups org.kernel.vger.linux-rdma,org.kernel.vger.linux-kernel,org.kernel.vger.linux-s390,org.kernel.vger.netdev
Message-ID <[email protected]>
On 29/07/26 5:55 pm, Alexandra Winter wrote:
>
> On 27.07.26 11:35, Hidayath Khan wrote:
>> dibs_lo_attach_dmb(), dibs_lo_detach_dmb() and dibs_lo_unregister_dmb()
>> look up the dmb_node under dmb_ht_lock, drop the lock and only then
>> operate on the node's refcount. Nothing keeps the node alive across
>> that window: __dibs_lo_unregister_dmb() removes the node from the hash
>> table under the write lock and immediately frees it.
>>
> I had lost track of this, but Rahul Chandelkar had already proposed a
> similar patch [1] for this issue, but never followed up with a v2.
>
> Rahul, Hidayath,
> Would it be ok for both of you to add
> Reported-by: Rahul Chandelkar <[email protected]>
Sure, happy to add Reported-by: Rahul Chandelkar <[email protected]> in v2.

>
>
> [1] https://lore.kernel.org/netdev/[email protected]/
>