Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
virtio-blk: don’t keep queue frozen during system suspend
Commit 4ce6e2db00de (“virtio-blk: Ensure no requests in virtqueues before deleting vqs.”) replaces queue quiesce with queue freeze in virtio-blk’s PM callbacks. And the motivation is to drain inflight IOs before suspending.
block layer’s queue freeze looks very handy, but it is also easy to cause deadlock, such as, any attempt to call into bio_queue_enter() may run into deadlock if the queue is frozen in current context. There are all kinds of ->suspend() called in suspend context, so keeping queue frozen in the whole suspend context isn’t one good idea. And Marek reported lockdep warning[1] caused by virtio-blk’s freeze queue in virtblk_freeze().
[1] https://lore.kernel.org/linux-block/[email protected]/
Given the motivation is to drain in-flight IOs, it can be done by calling freeze & unfreeze, meantime restore to previous behavior by keeping queue quiesced during suspend.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Debian 10 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.6 ESU | Released |
7 kernels
|
| Amazon Linux 2023 | Planned | — |
| Amazon Linux 2 5.10 | Will Not Fix | — |
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 18.04 AWS Focal | Released |
56 kernels
|
| Ubuntu 18.04 HWE Focal | Released |
69 kernels
|
| Ubuntu 20.04 | Released |
122 kernels
|
| Ubuntu 20.04 AWS | Released |
105 kernels
|
| Ubuntu 20.04 Azure | Released |
95 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
52 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
36 kernels
|
| Ubuntu 22.04 | Released |
69 kernels
|
| Ubuntu 22.04 AWS | Released |
60 kernels
|
| Ubuntu 22.04 Azure | Released |
56 kernels
|
| Ubuntu 24.04 | Released |
22 kernels
|
| Ubuntu 24.04 AWS | Ready For Release | — |