CVE-2026-74395

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference<br /> <br /> MLX5_IB_METHOD_DEVX_SUBSCRIBE_EVENT() links event_sub into sub_list<br /> before initializing the fields used by the shared error path.<br /> <br /> If eventfd_ctx_fdget() then fails, the unwind path dereferences<br /> event_sub-&gt;ev_file in uverbs_uobject_put() and calls<br /> subscribe_event_xa_dealloc() with an unset xa_key_level1.<br /> <br /> subscribe_event_xa_alloc() creates the XA entry exactly once for a given<br /> key_level1, on the first occurrence of that key. The unwind path must<br /> therefore call subscribe_event_xa_dealloc() exactly once for it as well.<br /> <br /> Enforce that by adding devx_key_in_sub_list() and calling<br /> subscribe_event_xa_dealloc() only when the last matching pending entry is<br /> being cleaned up.