Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
usb: free iso schedules on failed submit
EHCI and FOTG210 isochronous submits build an ehci_iso_sched before linking the URB to the endpoint queue, and keep the staged schedule in urb->hcpriv until iso_stream_schedule() and the link helpers consume it. If the controller is no longer accessible, or usb_hcd_link_urb_to_ep() fails, submit jumps to done_not_linked before that handoff happens and leaks the staged schedule still attached to urb->hcpriv.
Free the staged schedule from done_not_linked when submit fails before the URB is linked and clear urb->hcpriv after the free.
The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1.1.
An x86_64 allyesconfig build showed no new warnings. As we do not have an EHCI host controller with a USB isochronous device to test with, no runtime testing was able to be performed.
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:
- kernel-uek @ 5.4.17 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| CentOS 7 ELS | Planned | — |
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |