CVE-2021-47421 drm/amdgpu: handle the case of pci_channel_io_frozen only in amdgpu_pci_resume
A race condition in the AMD GPU driver can cause a deadlock during PCI error recovery, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47421?
CVE-2021-47421 is a high-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-667
Which versions are affected by CVE-2021-47421?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47421?
Apply the vendor's patch.
Is CVE-2021-47421 being exploited?
There is no known exploitation of CVE-2021-47421 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47421, GHSA-pxqq-3ph7-mw6w, ROOT-OS-DEBIAN-11-CVE-2021-47421, UBUNTU-CVE-2021-47421.