In the Linux kernel, the following vulnerability has been resolved: netem: fix return value if duplicate enqueue fails There is a bug in netem_enqueue() introduced by commit 5845f706388a ("net: netem: fix skb length BUG_ON in __skb_to_sgvec") that can lead to a use-after-free. This commit made netem_enqueue() always return NET_XMIT_SUCCESS when a packet is duplicated, which can cause the parent qdisc's q.qlen to be mistakenly incremented. When this happens qlen_notify() may be skipped on the parent during destruction, leaving a dangling pointer for some classful qdiscs like DRR. There are two ways for the bug happen: - If the duplicated packet is dropped by rootq->enqueue() and then the original packet is also dropped. - If rootq->enqueue() sends the duplicated packet to a different qdisc and the original packet is dropped. In both cases NET_XMIT_SUCCESS is returned even though no packets are enqueued at the netem qdisc. The fix is to defer the enqueue of the duplicate packet until after the original packet has been guaranteed to return NET_XMIT_SUCCESS.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netem: corregir valor de retorno si falla la puesta en cola duplicada Hay un error en netem_enqueue() introducido por el commit 5845f706388a ("net: netem: corregir BUG_ON de longitud de skb en __skb_to_sgvec") que puede provocar un use-after-free. Esta confirmación hizo que netem_enqueue() siempre devolviera NET_XMIT_SUCCESS cuando se duplica un paquete, lo que puede provocar que el q.qlen de la qdisc padre se incremente por error. Cuando esto sucede, es posible que qlen_notify() se omita en el padre durante la destrucción, dejando un puntero colgante para algunas qdisc con clase como DRR. Hay dos formas en las que ocurre el error: - Si el paquete duplicado se descarta mediante rootq->enqueue() y luego también se descarta el paquete original. - Si rootq->enqueue() envía el paquete duplicado a una qdisc diferente y se descarta el paquete original, en ambos casos se devuelve NET_XMIT_SUCCESS aunque no haya paquetes en cola en la qdisc netem. La solución es posponer la puesta en cola del paquete duplicado hasta que se haya garantizado que el paquete original devolverá NET_XMIT_SUCCESS.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-416
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d39fefc0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d39fc7c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36a7cbdc0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd3686e7600> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d39fc2c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd2d39fd840> | Operating System |
| linux | linux_kernel | 6.11 | <built-in method update of dict object at 0x7fd36b263d40> | Operating System |
| linux | linux_kernel | 6.11 | <built-in method update of dict object at 0x7fd3686e6400> | Operating System |
| linux | linux_kernel | 6.11 | <built-in method update of dict object at 0x7fd3686e6b00> | Operating System |
| linux | linux_kernel | 6.11 | <built-in method update of dict object at 0x7fd2d39fe340> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* |