Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
serial: 8250: Fix TX deadlock when using DMA
dmaengine_terminate_async does not guarantee that the
__dma_tx_complete callback will run. The callback is currently the
only place where dma->tx_running gets cleared. If the transaction is
canceled and the callback never runs, then dma->tx_running will never
get cleared and we will never schedule new TX DMA transactions again.
This change makes it so we clear dma->tx_running after we terminate
the DMA transaction. This is “safe” because serial8250_tx_dma_flush
is holding the UART port lock. The first thing the callback does is also
grab the UART port lock, so access to dma->tx_running is serialized.
Details
- Affected product:
- Ubuntu 20.04 ELS
- Affected packages:
- linux-meta @ 5.4.0
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 11 | Released |
3 kernels
|
| Debian 11 cloud | Released |
3 kernels
|
| Debian 13 | Planned | — |
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |