Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
ALSA: mtpav: shut down output timer before card teardown
snd_mtpav_output_timer() rearms chip->timer while holding chip->spinlock and accesses the card-private mtpav state.
snd_mtpav_free() currently takes the same lock and calls timer_delete() when the timer is active. This only removes a pending timer; it does not wait for a callback that is already running and does not prevent the callback from rearming the timer.
A callback running on another CPU can therefore continue after snd_mtpav_free() releases the lock and access the card-private state while the card is being torn down. It can also rearm the timer after timer_delete() has returned.
Call timer_shutdown_sync() without holding chip->spinlock. This waits for any running callback to finish and prevents further rearming before the card-private mtpav state is released.
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 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 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 @ 5.10.259 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.2 ESU | Planned | — |
| AlmaLinux 9.6 ESU | Planned | — |
| CentOS 7 ELS | Planned | — |