Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: defer exposing anon_fd until after copy_to_user() succeeds
After installing the anonymous fd, we can now see it in userland and close it. However, at this point we may not have gotten the reference count of the cache, but we will put it during colse fd, so this may cause a cache UAF.
So grab the cache reference count before fd_install(). In addition, by kernel convention, fd is taken over by the user land after fd_install(), and the kernel should not call close_fd() after that, i.e., it should call fd_install() after everything is ready, thus fd_install() is called after copy_to_user() succeeds.
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 5.14.0-11 (+2 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9 | Will Not Fix |
33 kernels
|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Planned | — |
| Oracle Linux 9 | Will Not Fix |
39 kernels
|
| RHEL 9 | Will Not Fix |
33 kernels
|
| Rocky Linux 9 | Will Not Fix |
33 kernels
|
| Ubuntu 24.04 | Will Not Fix |
7 kernels
|