Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
media: usbtv: keep device alive while ALSA card exists
The ALSA PCM callbacks store the driver state in pcm->private_data. An open PCM file can outlive USB disconnect because usbtv_audio_free() uses snd_card_free_when_closed(). The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream, so a later close dereferences freed memory in snd_usbtv_pcm_close().
Take a V4L2 device reference for the ALSA card and drop it from the card private_free callback. This keeps struct usbtv valid until ALSA has closed the remaining files and freed the card.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+13 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |