CVE-2021-47421: drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-21 · updated 2026-08-04
Weakness: CWE-667

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume In current code, when a PCI error state pci_channel_io_normal is detectd, it will report PCI_ERS_RESULT_CAN_RECOVER status to PCI driver, and PCI driver will continue the execution of PCI resume callback report_resume by pci_walk_bridge, and the callback will go into amdgpu_pci_resume finally, where write lock is releasd unconditionally without acquiring such lock first. In this case, a deadlock will happen when other threads start to acquire the read lock. To fix this, add a member in amdgpu_device strucutre to cache pci_channel_state, and only continue the execution in amdgpu_pci_resume when it's pci_channel_io_frozen.

Affected products

Linux kernel: from 5.10 before 5.10.241; from 5.11 before 5.14.12; 5.15-rc1, 5.15-rc2, 5.15-rc3, 5.15-rc4 — fixed in 5.10.241, 5.14.12

How to fix

Upgrade to a fixed version: Linux kernel 5.10.241, 5.14.12. Check the vendor advisory for mitigations.

References

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