Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: imx6q: fix out-of-bounds write when probed more than once
imx6_soc_volt is allocated fresh on every probe, sized to the number of ARM OPPs:
imx6_soc_volt = devm_kcalloc(cpu_dev, num, sizeof(*imx6_soc_volt), GFP_KERNEL);
but it is filled through soc_opp_count, which has static storage and is never reset. A second bind after an unbind keeps indexing from where the first one stopped, and writes past the end of the new array.
Unbinding and rebinding the driver on qemu’s mcimx6ul-evk, under KASAN:
BUG: KASAN: slab-out-of-bounds in imx6q_cpufreq_probe+0x3b0/0xa34 Write of size 4 at addr c5e90480 by task binder/73 imx6q_cpufreq_probe from platform_probe+0x88/0xe4 platform_probe from really_probe+0x108/0x384 bind_store from kernfs_fop_write_iter+0x1b4/0x28c
The write lands one u32 past the end of the allocation.
soc_opp_count is only read a few lines below the loop that fills it, so it never needed static storage. Make it a local.
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 | Will Not Fix |
17 kernels
|