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.
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Sat, 15 Aug 2026 17:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 |
Sat, 15 Aug 2026 06:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | RDMA/mlx5: Fix devx subscribe-event unwind NULL dereference | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:59:07.798Z
Reserved: 2026-08-15T05:44:03.891Z
Link: CVE-2026-74395
No data.
Status : Received
Published: 2026-08-15T06:22:41.480
Modified: 2026-08-15T06:22:41.480
Link: CVE-2026-74395
No data.
OpenCVE Enrichment
Updated: 2026-08-15T17:30:11Z
-
CWE-476
NULL Pointer Dereference