Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
mips: sched: Fix CPUMASK_OFFSTACK memory corruption
This patch addresses a critical memory management flaw. When CONFIG_CPUMASK_OFFSTACK is enabled, cpumask_var_t is a pointer. Consequently, sizeof(new_mask) evaluates to the pointer size, causing copy_from_user() to clobber the mask pointer. Furthermore, the old logic performed copy_from_user() before allocating the mask.
Fix this by allocating new_mask first. To handle variable-sized user masks correctly, use cpumask_size() to truncate overly large user masks or pad undersized masks with zeros before copying the data directly into the allocated buffer.
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 @ 4.19.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Will Not Fix |
42 kernels
|
| Debian 13 | Will Not Fix |
13 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 22.04 AWS | Planned | — |
| Ubuntu 22.04 Azure | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Will Not Fix | — |