CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's RDMA subsystem, specifically in the MLX5 driver, where improper handling of event subscriptions can lead to a NULL dereference during error path unwinding. This flaw may result in system instability or crashes, particularly impacting systems utilizing RDMA over the Mellanox hardware. Organizations using affected Linux distributions with RDMA capabilities should prioritize patching to mitigate potential disruptions.
Original NVD Description
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.