DocumentationOverview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
misc: nsm: pin the module while the device is open
misc_open() installs a misc driver’s file operations with fops_get(), which pins file_operations::owner before replacing the file’s f_op. The NSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does not take a module reference on the nsm driver.
If the driver is built as a module, an open file descriptor can therefore survive rmmod of the module that provides its ioctl callbacks. A later ioctl through that descriptor can call into unloaded module text.
Set nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module while any /dev/nsm file descriptor is open, matching the lifetime expectation for the installed file operations.
Details
- Affected product:
- Debian 10 ELS
- Affected packages:
- linux @ 4.19.0
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Will Not Fix | — |