Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
nfsd: Initialize ssc before laundromat_work to prevent NULL dereference
In nfs4_state_start_net(), laundromat_work may access nfsd_ssc through nfs4_laundromat -> nfsd4_ssc_expire_umount. If nfsd_ssc isn’t initialized, this can cause NULL pointer dereference.
Normally the delayed start of laundromat_work allows sufficient time for nfsd_ssc initialization to complete. However, when the kernel waits too long for userspace responses (e.g. in nfs4_state_start_net -> nfsd4_end_grace -> nfsd4_record_grace_done -> nfsd4_cld_grace_done -> cld_pipe_upcall -> __cld_pipe_upcall -> wait_for_completion path), the delayed work may start before nfsd_ssc initialization finishes.
Fix this by moving nfsd_ssc initialization before starting laundromat_work.
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 5.14.0 (+1 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.2 ESU | Released |
16 kernels
|
| AlmaLinux 9.6 ESU | Released |
3 kernels
|
| Amazon Linux 2023 | Planned | — |
| Debian 11 | Released |
5 kernels
|
| Debian 11 cloud | Released |
5 kernels
|
| Debian 12 | Released |
28 kernels
|
| Oracle Linux 8 UEK 7 | Released |
70 kernels
|
| Oracle Linux 9 UEK 7 | Released |
70 kernels
|
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
57 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
40 kernels
|
| Ubuntu 22.04 | Released |
81 kernels
|
| Ubuntu 22.04 AWS | Released |
72 kernels
|
| Ubuntu 22.04 Azure | Released |
66 kernels
|
| Ubuntu 24.04 | Released |
37 kernels
|