Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
mmc: mxcmmc: cancel data work and watchdog on remove
mxcmci_remove() frees the host through the devm tail, but neither it nor mmc_remove_host() drains the driver’s own asynchronous state. host->watchdog, a 10 s timer armed on the DMA path in mxcmci_setup_data(), is deleted only by the DMA- and IRQ-complete paths, which the remove path does not explicitly drain; it can therefore fire after the host is freed and dereference it in mxcmci_watchdog(). host->datawork, armed from the IRQ handler on the PIO path, is not cancelled by the remove path either.
Free the devm-registered IRQ, then cancel datawork and delete the watchdog in mxcmci_remove(), before dma_release_channel(). Freeing the IRQ first keeps a trailing handler from re-arming datawork between the cancel and the host free. Both callbacks are non-self-rearming.
This issue was found by an in-house static analysis tool.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 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 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 @ 5.4.0 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |