CVE-2026-43061

Description

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.

References

• https://git.kernel.org/stable/c/2a72403b985aea6b4aac3171830492f9a387f9e1
• https://git.kernel.org/stable/c/5f6b17562f03fc65c7d3474ef8f1959b19d1ca41
• https://git.kernel.org/stable/c/79a19bd936bb35f56ef0ccab1b3b59ebce8c762d
• https://git.kernel.org/stable/c/8190f9ab6ad90cb97652adbebd238b874a4ef70d
• https://git.kernel.org/stable/c/a424a34b8faddf97b5af41689087e7a230f79ba7