CVE-2026-80886
In the Linux kernel, the following vulnerability has been resolved: serial: msm: Disable DMA for kernel console UART At the moment, concurrent writes from userspace and the kernel to the console can trigger a race condition that results in an infinite…
Does this matter?
Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published.
Description
In the Linux kernel, the following vulnerability has been resolved: serial: msm: Disable DMA for kernel console UART At the moment, concurrent writes from userspace and the kernel to the console can trigger a race condition that results in an infinite loop of the same messages printed over and over again. This is most likely to happen during system startup or shutdown when the init system starts/stops a large number of system services that interact with various kernel code. When userspace writes to the TTY device, the driver initiates an asynchronous DMA transfer and releases the port lock. At the same moment, the kernel printk path might grab the port lock and re-configure the UART controller for PIO, without waiting for the DMA operation to complete. It seems like this collision results in zero progress being reported for the DMA engine, so the same text is printed to the console over and over again. For the kernel console, we want a reliable output path that will be functional even during crashes etc. So rather than implementing complex code to synchronize the kernel console write routines with the userspace DMA write routines, simply disable DMA for the console UART instance. Similar checks exist in many other serial drivers, e.g. 8250_port.c, imx.c, sh-sci.c etc.
- CVSS
- Not yet scored
- EPSS
- 0.18% probability · 8th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/22dd2777e6c180e1c945b00f6d18550979436324
- https://git.kernel.org/stable/c/2727744ccb5ca59090451451ee94f530b1be04a5
- https://git.kernel.org/stable/c/6acea62738ed4cae6746483026706a773b44dad7
- https://git.kernel.org/stable/c/abc1926c88c189e5d698b91ed6890e09ab5c321d
- https://git.kernel.org/stable/c/bb4296de5b538b575978c588cb3738ab8524d01a
- https://git.kernel.org/stable/c/d354716245192de2d203f2b35f22ab8dc13595e2
- https://git.kernel.org/stable/c/e3b42e326f4f30efcdc90bad5f5ba37e1cd91a47
- https://git.kernel.org/stable/c/f58e568dc308c8e13f7730c8de2da5ed514e540d
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.