fkie_cve-2024-35839
Vulnerability from fkie_nvd
Published
2024-05-17 15:15
Modified
2024-11-21 09:21
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
netfilter: bridge: replace physindev with physinif in nf_bridge_info
An skb can be added to a neigh->arp_queue while waiting for an arp
reply. Where original skb's skb->dev can be different to neigh's
neigh->dev. For instance in case of bridging dnated skb from one veth to
another, the skb would be added to a neigh->arp_queue of the bridge.
As skb->dev can be reset back to nf_bridge->physindev and used, and as
there is no explicit mechanism that prevents this physindev from been
freed under us (for instance neigh_flush_dev doesn't cleanup skbs from
different device's neigh queue) we can crash on e.g. this stack:
arp_process
neigh_update
skb = __skb_dequeue(&neigh->arp_queue)
neigh_resolve_output(..., skb)
...
br_nf_dev_xmit
br_nf_pre_routing_finish_bridge_slow
skb->dev = nf_bridge->physindev
br_handle_frame_finish
Let's use plain ifindex instead of net_device link. To peek into the
original net_device we will use dev_get_by_index_rcu(). Thus either we
get device and are safe to use it or we don't get it and drop skb.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: replace physindev with physinif in nf_bridge_info\n\nAn skb can be added to a neigh-\u003earp_queue while waiting for an arp\nreply. Where original skb\u0027s skb-\u003edev can be different to neigh\u0027s\nneigh-\u003edev. For instance in case of bridging dnated skb from one veth to\nanother, the skb would be added to a neigh-\u003earp_queue of the bridge.\n\nAs skb-\u003edev can be reset back to nf_bridge-\u003ephysindev and used, and as\nthere is no explicit mechanism that prevents this physindev from been\nfreed under us (for instance neigh_flush_dev doesn\u0027t cleanup skbs from\ndifferent device\u0027s neigh queue) we can crash on e.g. this stack:\n\narp_process\n neigh_update\n skb = __skb_dequeue(\u0026neigh-\u003earp_queue)\n neigh_resolve_output(..., skb)\n ...\n br_nf_dev_xmit\n br_nf_pre_routing_finish_bridge_slow\n skb-\u003edev = nf_bridge-\u003ephysindev\n br_handle_frame_finish\n\nLet\u0027s use plain ifindex instead of net_device link. To peek into the\noriginal net_device we will use dev_get_by_index_rcu(). Thus either we\nget device and are safe to use it or we don\u0027t get it and drop skb."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netfilter: bridge: reemplace physindev con physinif en nf_bridge_info. Se puede agregar un skb a neigh-\u0026gt;arp_queue mientras se espera una respuesta de arp. Donde skb-\u0026gt;dev del skb original puede ser diferente al neigh-\u0026gt;dev de neigh. Por ejemplo, en el caso de unir un skb designado de un veth a otro, el skb se agregar\u00eda a un vecino-\u0026gt;arp_queue del puente. Como skb-\u0026gt;dev se puede restablecer a nf_bridge-\u0026gt;physindev y usarse, y como no existe un mecanismo expl\u00edcito que impida que este physindev se libere bajo nuestra responsabilidad (por ejemplo, neigh_flush_dev no limpia skbs de la cola vecina de diferentes dispositivos), podemos crashear, por ejemplo, en esta pila: arp_process neigh_update skb = __skb_dequeue(\u0026amp;neigh-\u0026gt;arp_queue) neigh_resolve_output(..., skb) ... br_nf_dev_xmit br_nf_pre_routing_finish_bridge_slow skb-\u0026gt;dev = nf_bridge-\u0026gt;physindev br_handle_frame_finish Usemos ifindex simple en lugar de enlace net_device. Para echar un vistazo al net_device original usaremos dev_get_by_index_rcu(). Por lo tanto, o obtenemos el dispositivo y podemos usarlo con seguridad o no lo obtenemos y eliminamos skb."
}
],
"id": "CVE-2024-35839",
"lastModified": "2024-11-21T09:21:01.073",
"metrics": {},
"published": "2024-05-17T15:15:21.017",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/544add1f1cfb78c3dfa3e6edcf4668f6be5e730c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7ae19ee81ca56b13c50a78de6c47d5b8fdc9d97b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9325e3188a9cf3f69fc6f32af59844bbc5b90547"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9874808878d9eed407e3977fd11fee49de1e1d86"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/544add1f1cfb78c3dfa3e6edcf4668f6be5e730c"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/7ae19ee81ca56b13c50a78de6c47d5b8fdc9d97b"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/9325e3188a9cf3f69fc6f32af59844bbc5b90547"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/9874808878d9eed407e3977fd11fee49de1e1d86"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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