Cloudanix VulnDB

CVE-2021-47019

None

CVSS

—

EPSS

0.2%

Published

Feb 28, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A timing problem in certain Wi-Fi hardware drivers can cause computers to crash when they go to sleep or wake up.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Race condition between PCIe suspend and pending IRQ tasklet allows mt7921 driver to perform register reads/writes after the host controller has suspended, resulting in invalid memory access and kernel panic.

Why it matters to the business

Unexpected system crashes and loss of availability on devices using mt7921 Wi-Fi hardware during power state transitions; low exploitation likelihood limits widespread operational disruption.

How an attack unfolds

An attacker with local access triggers a suspend event while the mt7921 IRQ tasklet remains queued; the tasklet executes after the PCIe link is suspended, dereferencing invalid registers and crashing the kernel.

How to fix it

Update the Linux kernel to a version containing the mt76 mt7921 suspend IRQ synchronization fix; disable the mt7921 device or block suspend transitions as a temporary workaround if patching is delayed.

How to confirm the fix worked

Confirm kernel version includes the referenced mt76 commit; reproduce suspend/resume cycles under load and verify absence of mt7921e IRQ tasklet panics in dmesg; inspect driver source for the added disable_irq + synchronize_irq sequence.

Typical attack path

  1. Obtain local execution on affected Linux system with mt7921 hardware
  2. Force or wait for system suspend transition
  3. Allow pending IRQ to be scheduled after pci_pm_suspend completes
  4. Trigger invalid register access in mt76_mmio_rr leading to panic

How to detect it

Review kernel logs for mt7921e IRQ tasklet stack traces containing mt76_mmio_rr calls after suspend events; correlate with pci_pm_suspend traces and kernel panic messages indicating fatal interrupt exceptions.

What your security team should do

  • Prioritize kernel updates on systems containing mt7921 hardware
  • Monitor for kernel oops/panic logs referencing mt7921_irq_tasklet
  • Apply vendor firmware or distro backports within standard patch windows given low EPSS

The record

In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix possible invalid register access Disable the interrupt and synchronze for the pending irq handlers to ensure the irq tasklet is not being scheduled after the suspend to avoid the possible invalid register access acts when the host pcie controller is suspended. [17932.910534] mt7921e 0000:01:00.0: pci_pm_suspend+0x0/0x22c returned 0 after 21375 usecs [17932.910590] pcieport 0000:00:00.0: calling pci_pm_suspend+0x0/0x22c @ 18565, parent: pci0000:00 [17932.910602] pcieport 0000:00:00.0: pci_pm_suspend+0x0/0x22c returned 0 after 8 usecs [17932.910671] mtk-pcie 11230000.pcie: calling platform_pm_suspend+0x0/0x60 @ 22783, parent: soc [17932.910674] mtk-pcie 11230000.pcie: platform_pm_suspend+0x0/0x60 returned 0 after 0 usecs ... 17933.615352] x1 : 00000000000d4200 x0 : ffffff8269ca2300 [17933.620666] Call trace: [17933.623127] mt76_mmio_rr+0x28/0xf0 [mt76] [17933.627234] mt7921_rr+0x38/0x44 [mt7921e] [17933.631339] mt7921_irq_tasklet+0x54/0x1d8 [mt7921e] [17933.636309] tasklet_action_common+0x12c/0x16c [17933.640754] tasklet_action+0x24/0x2c [17933.644418] __do_softirq+0x16c/0x344 [17933.648082] irq_exit+0xa8/0xac [17933.651224] scheduler_ipi+0xd4/0x148 [17933.654890] handle_IPI+0x164/0x2d4 [17933.658379] gic_handle_irq+0x140/0x178 [17933.662216] el1_irq+0xb8/0x180 [17933.665361] cpuidle_enter_state+0xf8/0x204 [17933.669544] cpuidle_enter+0x38/0x4c [17933.673122] do_idle+0x1a4/0x2a8 [17933.676352] cpu_startup_entry+0x24/0x28 [17933.680276] rest_init+0xd4/0xe0 [17933.683508] arch_call_rest_init+0x10/0x18 [17933.687606] start_kernel+0x340/0x3b4 [17933.691279] Code: aa0003f5 d503201f f953eaa8 8b344108 (b9400113) [17933.697373] ---[ end trace a24b8e26ffbda3c5 ]--- [17933.767846] Kernel panic - not syncing: Fatal exception in interrupt

Affected packages

Ecosystem Package Introduced Fixed
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 5.4.0-9.12
Ubuntu:20.04:LTS linux-aws 0 5.4.0-1005.5
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 5.15.0-1014.18~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 5.4.0-1006.6
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 5.15.0-1007.8~20.04.1
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 5.15.0-1019.24~20.04.1.1
Ubuntu:20.04:LTS linux-bluefield 0 5.4.0-1007.10
Ubuntu:20.04:LTS linux-gcp 0 5.4.0-1005.5
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 5.15.0-1006.9~20.04.1
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 5.4.0-1008.9
Ubuntu:20.04:LTS linux-gkeop-5.15 0 5.15.0-1003.5~20.04.2
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 5.15.0-33.34~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 5.4.0-1003.4
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1033.36~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1003.5~20.04.1
Ubuntu:20.04:LTS linux-iot 0 5.4.0-1001.3
Ubuntu:20.04:LTS linux-kvm 0 5.4.0-1004.4
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-33.34~20.04.1
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 5.4.0-1005.5
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 5.15.0-1007.9~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 5.4.0-1007.7
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 5.15.0-1015.17~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 5.4.0-1020.24
Ubuntu:22.04:LTS linux 0 5.13.0-19.19
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.13.0-1005.6
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 6.5.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-azure 0 5.13.0-1006.7
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 6.5.0-1007.7~22.04.1
Ubuntu:22.04:LTS linux-azure-fde 0 5.15.0-1019.24.1
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 5.13.0-1005.6
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 6.5.0-1010.10~22.04.3
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1001.2
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 6.5.0-14.14~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1002.2
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1004.6
Ubuntu:22.04:LTS linux-kvm 0 5.13.0-1004.4
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-22.22
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 6.5.0-14.14.1~22.04.1
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1005.5
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 6.5.0-1004.4
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1008.8~22.04.1
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix
Ubuntu:22.04:LTS linux-oem-6.5 0 6.5.0-1003.3
Ubuntu:22.04:LTS linux-oracle 0 5.13.0-1008.10
Ubuntu:22.04:LTS linux-oracle-6.5 0 6.5.0-1013.13~22.04.4
Ubuntu:22.04:LTS linux-raspi 0 5.13.0-1008.9
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 6.5.0-17.17.1.1~22.04.1
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 6.5.0-1007.8~22.04.1
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 5.15.0-1022.26
Ubuntu:24.04:LTS linux 0 6.5.0-9.9
Ubuntu:24.04:LTS linux-aws 0 6.5.0-1008.8
Ubuntu:24.04:LTS linux-azure 0 6.5.0-1007.7
Ubuntu:24.04:LTS linux-gcp 0 6.5.0-1007.7
Ubuntu:24.04:LTS linux-gke 0 6.8.0-1003.5
Ubuntu:24.04:LTS linux-gkeop 0 6.8.0-1001.3
Ubuntu:24.04:LTS linux-ibm 0 6.5.0-1009.9
Ubuntu:24.04:LTS linux-lowlatency 0 6.5.0-9.9.1
Ubuntu:24.04:LTS linux-nvidia 0 6.8.0-1007.7
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 6.8.0-1009.9.1
Ubuntu:24.04:LTS linux-oem-6.8 0 6.8.0-1003.3
Ubuntu:24.04:LTS linux-oracle 0 6.5.0-1010.10
Ubuntu:24.04:LTS linux-raspi 0 6.5.0-1005.7
Ubuntu:24.04:LTS linux-riscv 0 6.5.0-9.9.1
Ubuntu:Pro:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-oem 0 No fix
Ubuntu:Pro:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-gke 0 No fix
Ubuntu:Pro:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:Pro:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:Pro:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:Pro:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:Pro:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:Pro:20.04:LTS linux-raspi2 0 No fix
Ubuntu:Pro:20.04:LTS linux-riscv 0 No fix
Ubuntu:Pro:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:Pro:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-aws-fips 0 4.15.0-2000.4
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-azure-fips 0 4.15.0-1002.2
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-fips 0 4.15.0-1027.32
Ubuntu:Pro:FIPS-updates:18.04:LTS linux-gcp-fips 0 4.15.0-2013.14
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-aws-fips 0 5.4.0-1021.21+fips2
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-azure-fips 0 5.4.0-1022.22+fips1
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-fips 0 5.4.0-1026.30
Ubuntu:Pro:FIPS-updates:20.04:LTS linux-gcp-fips 0 5.4.0-1021.21+fips1
Ubuntu:Pro:FIPS:16.04:LTS linux-fips 0 4.4.0-1003.3
Ubuntu:Pro:FIPS:18.04:LTS linux-aws-fips 0 4.15.0-2000.4
Ubuntu:Pro:FIPS:18.04:LTS linux-azure-fips 0 4.15.0-1002.2
Ubuntu:Pro:FIPS:18.04:LTS linux-fips 0 4.15.0-1011.12
Ubuntu:Pro:FIPS:18.04:LTS linux-gcp-fips 0 4.15.0-1001.1
Ubuntu:Pro:FIPS:20.04:LTS linux-aws-fips 0 5.4.0-1021.21+fips2
Ubuntu:Pro:FIPS:20.04:LTS linux-azure-fips 0 5.4.0-1022.22+fips1
Ubuntu:Pro:FIPS:20.04:LTS linux-fips 0 5.4.0-1007.8
Ubuntu:Pro:FIPS:20.04:LTS linux-gcp-fips 0 5.4.0-1021.21+fips1

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