Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference
MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT() links event_sub into sub_list before initializing the fields used by the shared error path.
If eventfd_ctx_fdget() then fails, the unwind path dereferences event_sub->ev_file in uverbs_uobject_put() and calls subscribe_event_xa_dealloc() with an unset xa_key_level1.
subscribe_event_xa_alloc() creates the XA entry exactly once for a given key_level1, on the first occurrence of that key. The unwind path must therefore call subscribe_event_xa_dealloc() exactly once for it as well.
Enforce that by adding devx_key_in_sub_list() and calling subscribe_event_xa_dealloc() only when the last matching pending entry is being cleaned up.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.10.259 (+2 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |