CVE-2021-47399

ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

ixgbe: Fix NULL pointer dereference in ixgbe_xdp_setup

The ixgbe driver currently generates a NULL pointer dereference with
some machine (online cpus < 63). This is due to the fact that the
maximum value of num_xdp_queues is nr_cpu_ids. Code is in
"ixgbe_set_rss_queues"".

Here's how the problem repeats itself:
Some machine (online cpus < 63), And user set num_queues to 63 through
ethtool. Code is in the "ixgbe_set_channels",
adapter->ring_feature[RING_F_FDIR].limit = count;

It becomes 63.

When user use xdp, "ixgbe_set_rss_queues" will set queues num.
adapter->num_rx_queues = rss_i;
adapter->num_tx_queues = rss_i;
adapter->num_xdp_queues = ixgbe_xdp_queues(adapter);

And rss_i's value is from
f = &adapter->ring_feature[RING_F_FDIR];
rss_i = f->indices = f->limit;

So "num_rx_queues" > "num_xdp_queues", when run to "ixgbe_xdp_setup",
for (i = 0; i < adapter->num_rx_queues; i++)
if (adapter->xdp_ring[i]->xsk_umem)

It leads to panic.

Call trace:
[exception RIP: ixgbe_xdp+368]
RIP: ffffffffc02a76a0 RSP: ffff9fe16202f8d0 RFLAGS: 00010297
RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000000000001c RDI: ffffffffa94ead90
RBP: ffff92f8f24c0c18 R8: 0000000000000000 R9: 0000000000000000
R10: ffff9fe16202f830 R11: 0000000000000000 R12: ffff92f8f24c0000
R13: ffff9fe16202fc01 R14: 000000000000000a R15: ffffffffc02a7530
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
7 [ffff9fe16202f8f0] dev_xdp_install at ffffffffa89fbbcc
8 [ffff9fe16202f920] dev_change_xdp_fd at ffffffffa8a08808
9 [ffff9fe16202f960] do_setlink at ffffffffa8a20235
10 [ffff9fe16202fa88] rtnl_setlink at ffffffffa8a20384
11 [ffff9fe16202fc78] rtnetlink_rcv_msg at ffffffffa8a1a8dd
12 [ffff9fe16202fcf0] netlink_rcv_skb at ffffffffa8a717eb
13 [ffff9fe16202fd40] netlink_unicast at ffffffffa8a70f88
14 [ffff9fe16202fd80] netlink_sendmsg at ffffffffa8a71319
15 [ffff9fe16202fdf0] sock_sendmsg at ffffffffa89df290
16 [ffff9fe16202fe08] __sys_sendto at ffffffffa89e19c8
17 [ffff9fe16202ff30] __x64_sys_sendto at ffffffffa89e1a64
18 [ffff9fe16202ff38] do_syscall_64 at ffffffffa84042b9
19 [ffff9fe16202ff50] entry_SYSCALL_64_after_hwframe at ffffffffa8c0008c

So I fix ixgbe_max_channels so that it will not allow a setting of queues
to be higher than the num_online_cpus(). And when run to ixgbe_xdp_setup,
take the smaller value of num_rx_queues and num_xdp_queues.

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: ixgbe: corrige la desreferencia del puntero NULL en ixgbe_xdp_setup. El controlador ixgbe actualmente genera una desreferencia del puntero NULL con alguna máquina (cpus en línea <63). Esto se debe al hecho de que el valor máximo de num_xdp_queues es nr_cpu_ids. El código está en "ixgbe_set_rss_queues"". Así es como el problema se repite: alguna máquina (cpus en línea <63), y el usuario configuró num_queues en 63 a través de ethtool. El código está en "ixgbe_set_channels", adaptador->ring_feature[RING_F_FDIR].limit = count; se convierte en 63. Cuando el usuario usa xdp, "ixgbe_set_rss_queues" establecerá el número de colas adaptor->num_rx_queues = rss_i; = &adapter->ring_feature[RING_F_FDIR]; rss_i = f->indices = f->limit; Entonces "num_rx_queues" > "num_xdp_queues", cuando se ejecuta en "ixgbe_xdp_setup", para (i = 0; i < adaptor->num_rx_queues; i++) if (adapter->xdp_ring[i]->xsk_umem) Genera pánico: [excepción RIP: ixgbe_xdp+368] RIP: ffffffffc02a76a0 RSP: ffff9fe16202f8d0 RFLAGS: 00010297 RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000000 RDX : 0000000000000000 RSI: 000000000000001c RDI: ffffffffa94ead90 RBP: ffff92f8f24c0c18 R8: 0000000000000000 R9: 0000000000000000 R10: ffff9fe1620 2f830 R11: 0000000000000000 R12: ffff92f8f24c0000 R13: ffff9fe16202fc01 R14: 000000000000000a R15: ffffffffc02a7530 ORIG_RAX: ffffffffffffffff CS: : 0018 7 [ffff9fe16202f8f0] dev_xdp_install en fffffffa89fbbcc 8 [ffff9fe16202f920] dev_change_xdp_fd en fffffffa8a08808 9 [ffff9fe16202f960] do_setlink en fffffffa8a20235 10 [ffff9fe16202fa88] rtnl_setlink en fffffffa8a20384 11 [ffff9fe16202fc78] rtnetlink_rcv_msg en ffffffffa8a1a8dd 12 [ffff9fe16202fcf0] netlink_rcv_skb en ffffffffa8a717eb 13 [ffff9fe16202fd40] netlink_unicast en fffffffa8a70f88 14 [ffff9fe162 02fd80] netlink_sendmsg en fffffffa8a71319 15 [ffff9fe16202fdf0] sock_sendmsg en ffffffffa89df290 16 [ffff9fe16202fe08] __sys_sendto en ffffffffa89e19c8 17 [ffff9fe16202ff30] __x64_sys_sendto en ffffffffa89e1a64 8 [ffff9fe16202ff38] do_syscall_64 en ffffffffa84042b9 19 [ffff9fe16202ff50] Entry_SYSCALL_64_after_hwframe en ffffffffa8c0008c Entonces arreglo ixgbe_max_channels para que no permita una configuración de colas ser mayor que num_online_cpus(). Y cuando ejecute ixgbe_xdp_setup, tome el valor más pequeño de num_rx_queues y num_xdp_queues.

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-12-19 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (4)

URL	Tag	Source
https://git.kernel.org/stable/c/4a9b32f30f805ca596d76605903a48eab58e0b88	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/20f6c4a31a525edd9ea6243712b868ba0e4e331e	2021-10-06
https://git.kernel.org/stable/c/2744341dd52e935344ca1b4bf189ba0d182a3e8e	2021-10-07
https://git.kernel.org/stable/c/513e605d7a9ce136886cb42ebb2c40e9a6eb6333	2021-09-29

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.0 < 5.10.71 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.10.71"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.0 < 5.14.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.14.10"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.0 < 5.15 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.0 < 5.15"		en		Affected