Cloudanix VulnDB

CVE-2024-26996

None

CVSS

—

EPSS

0.2%

Published

May 1, 2024

CISA due date

—

Cloudanix analysis

Monitor only SSVC: Track

A bug in Linux USB network handling can let attackers crash devices or potentially take them over by messing with connection restarts.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Use After Free
Remediation
Patch
Effort
Low
Patch risk
Low

What it actually does

Use-after-free in the Linux kernel NCM USB gadget driver where ncm object is freed during unbind but dev->port_usb remains associated, leading to dereference of released memory on subsequent bind and eth_start_xmit.

Why it matters to the business

Kernel crashes or potential remote code execution on systems using USB gadget NCM networking, causing denial of service or full system compromise especially in embedded or Android-like environments.

How an attack unfolds

An attacker forces a USB transport error during interface stop, prevents proper disconnect in ncm_disable, frees the ncm object on unbind, then triggers rebind and interface up to dereference the freed object via eth_start_xmit and dev->wrap.

How to fix it

Apply the upstream kernel patch that checks ncm->netdev before calling gether_disconnect in ncm_disable; rebuild and deploy updated kernel images to all affected devices.

How to confirm the fix worked

Confirm kernel source contains the ncm_disable netdev NULL check; test by simulating usb_ep_enable failure during link down and verifying no UAF on rebind and interface up.

Typical attack path

  1. Trigger eth_stop on usb0 interface
  2. Induce usb_ep_enable error so in_ep remains disabled
  3. Invoke ncm_disable without calling gether_disconnect
  4. Perform ncm_unbind and ncm_free releasing the object
  5. Rebind new ncm instance while stale port_usb association persists
  6. Bring interface up and invoke eth_start_xmit to dereference freed memory

How to detect it

Search kernel logs for paging request at invalid addresses during eth_start_xmit or f_ncm unbind sequences; inspect for repeated ncm_alloc after ncm_free without intervening gether_disconnect.

What your security team should do

  • Prioritize kernel updates on all USB gadget NCM deployments
  • Monitor for kernel oops involving f_ncm and dead memory addresses
  • Disable NCM gadget function where not required

The record

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error When ncm function is working and then stop usb0 interface for link down, eth_stop() is called. At this piont, accidentally if usb transport error should happen in usb_ep_enable(), 'in_ep' and/or 'out_ep' may not be enabled. After that, ncm_disable() is called to disable for ncm unbind but gether_disconnect() is never called since 'in_ep' is not enabled. As the result, ncm object is released in ncm unbind but 'dev->port_usb' associated to 'ncm->port' is not NULL. And when ncm bind again to recover netdev, ncm object is reallocated but usb0 interface is already associated to previous released ncm object. Therefore, once usb0 interface is up and eth_start_xmit() is called, released ncm object is dereferrenced and it might cause use-after-free memory. [function unlink via configfs] usb0: eth_stop dev->port_usb=ffffff9b179c3200 --> error happens in usb_ep_enable(). NCM: ncm_disable: ncm=ffffff9b179c3200 --> no gether_disconnect() since ncm->port.in_ep->enabled is false. NCM: ncm_unbind: ncm unbind ncm=ffffff9b179c3200 NCM: ncm_free: ncm free ncm=ffffff9b179c3200 <-- released ncm [function link via configfs] NCM: ncm_alloc: ncm alloc ncm=ffffff9ac4f8a000 NCM: ncm_bind: ncm bind ncm=ffffff9ac4f8a000 NCM: ncm_set_alt: ncm=ffffff9ac4f8a000 alt=0 usb0: eth_open dev->port_usb=ffffff9b179c3200 <-- previous released ncm usb0: eth_start dev->port_usb=ffffff9b179c3200 <-- eth_start_xmit() --> dev->wrap() Unable to handle kernel paging request at virtual address dead00000000014f This patch addresses the issue by checking if 'ncm->netdev' is not NULL at ncm_disable() to call gether_disconnect() to deassociate 'dev->port_usb'. It's more reasonable to check 'ncm->netdev' to call gether_connect/disconnect rather than check 'ncm->port.in_ep->enabled' since it might not be enabled but the gether connection might be established.

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 No fix
Debian:12 linux 0 6.1.90-1
Debian:13 linux 0 6.8.9-1
Linux Kernel 0 5.15.157
Linux Kernel 4.4.0 5.15.157
Mageia:9 dwarves 0 1.27-1.mga9
Mageia:9 kernel 0 6.6.37-1.mga9
Mageia:9 kernel-linus 0 6.6.37-1.mga9
Mageia:9 kmod-virtualbox 0 7.0.18-50.mga9
Mageia:9 kmod-xtables-addons 0 3.24-59.mga9
SUSE:Linux Enterprise High Availability Extension 12 SP5 kernel-default 0 4.12.14-122.219.1
SUSE:Linux Enterprise High Availability Extension 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Live Patching 12 SP5 kernel-default 0 4.12.14-122.219.1
SUSE:Linux Enterprise Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_57 0 1-8.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5-RT_Update_16 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_15 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_1 0 1-150600.1.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_1 0 1-150600.13.3.7
SUSE:Linux Enterprise Micro 5.5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Micro 5.5 kernel-default-base 0 5.14.21-150500.55.68.1.150500.6.31.1
SUSE:Linux Enterprise Micro 5.5 kernel-rt 0 5.14.21-150500.13.58.1
SUSE:Linux Enterprise Micro 5.5 kernel-source-rt 0 5.14.21-150500.13.58.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-64kb 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default-base 0 5.14.21-150500.55.68.1.150500.6.31.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-source 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-zfcpdump 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.7.3.150600.12.2.7
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.7.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-docs 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-obs-build 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-source 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-syms 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.7.4
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.7.2
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.7.1
SUSE:Linux Enterprise Module for Legacy 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-syms-azure 0 5.14.21-150500.33.57.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.5.4
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.5.4
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.5.1
SUSE:Linux Enterprise Real Time 12 SP5 kernel-rt 0 4.12.14-10.188.1
SUSE:Linux Enterprise Real Time 12 SP5 kernel-rt_debug 0 4.12.14-10.188.1
SUSE:Linux Enterprise Real Time 12 SP5 kernel-source-rt 0 4.12.14-10.188.1
SUSE:Linux Enterprise Real Time 12 SP5 kernel-syms-rt 0 4.12.14-10.188.1
SUSE:Linux Enterprise Server 12 SP5 kernel-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5 kernel-default 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server 12 SP5 kernel-source 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server 12 SP5 kernel-source-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5 kernel-syms 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server 12 SP5 kernel-syms-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-default 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-source 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-source-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-syms 0 4.12.14-122.219.1
SUSE:Linux Enterprise Server for SAP Applications 12 SP5 kernel-syms-azure 0 4.12.14-16.188.1
SUSE:Linux Enterprise Software Development Kit 12 SP5 kernel-docs 0 4.12.14-122.219.1
SUSE:Linux Enterprise Software Development Kit 12 SP5 kernel-obs-build 0 4.12.14-122.219.1
SUSE:Linux Enterprise Workstation Extension 12 SP5 kernel-default 0 4.12.14-122.219.1
SUSE:Linux Enterprise Workstation Extension 15 SP5 kernel-default 0 5.14.21-150500.55.68.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.7.3
SUSE:Real Time Module 15 SP5 kernel-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-rt_debug 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-source-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP5 kernel-syms-rt 0 5.14.21-150500.13.58.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.5.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.5.1
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:20.04:LTS linux 0 No fix
Ubuntu:20.04:LTS linux 0 5.4.0-216.236
Ubuntu:20.04:LTS linux-aws 0 No fix
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1146.156
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 5.15.0-1065.71~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1151.158
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 5.15.0-1068.77~20.04.1
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 5.15.0-1068.77~20.04.1.1
Ubuntu:20.04:LTS linux-bluefield 0 No fix
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1105.112
Ubuntu:20.04:LTS linux-gcp 0 No fix
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1149.158
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 5.15.0-1065.73~20.04.1
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 No fix
Ubuntu:20.04:LTS linux-gkeop-5.15 0 5.15.0-1048.55~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 5.15.0-116.126~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1092.97
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1058.61~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1060.66~20.04.1
Ubuntu:20.04:LTS linux-iot 0 No fix
Ubuntu:20.04:LTS linux-kvm 0 No fix
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1133.142
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-116.126~20.04.1
Ubuntu:20.04:LTS linux-nvidia-tegra-5.15 0 5.15.0-1027.27~20.04.1
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 5.4.0-1144.154
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 5.15.0-1063.69~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1129.142
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 5.15.0-1061.65~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 5.4.0-1064.68
Ubuntu:22.04:LTS linux 0 5.15.0-116.126
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.15.0-1065.71
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 6.8.0-1011.12~22.04.1
Ubuntu:22.04:LTS linux-azure 0 5.15.0-1068.77
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 6.8.0-1010.10~22.04.1
Ubuntu:22.04:LTS linux-azure-fde 0 5.15.0-1068.77.1
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 5.15.0-1064.72
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1010.11~22.04.1
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1062.68
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1048.55
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-38.38~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1058.61
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1060.66
Ubuntu:22.04:LTS linux-kvm 0 5.15.0-1062.67
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-116.126
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 6.8.0-38.38.1~22.04.2
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1060.61
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1009.9~22.04.1
Ubuntu:22.04:LTS linux-nvidia-tegra 0 5.15.0-1026.26
Ubuntu:22.04:LTS linux-nvidia-tegra-igx 0 5.15.0-1015.15
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix

Related vulnerabilities