CVE-2026-74395

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 6e15b770461eeaa0ff73934922cb670a6a9db04eaffected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 9be9aca28424228586fe9211c373ebdb826ebb6caffected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < f345e744b6b087188cde2377da5cbe9713b61353affected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 1025dc2f7ba29b04b8687790fa91f9cd1a53141eaffected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 7921821fc2b19c01588311f6e7468ae5b68b1f61affected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 5100febf8e9d6c8c5ba8dc6534c6a5e3376e5989affected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 78b9589fda266c71f0f9d0c858d4fa7381a890a5affected
LinuxLinux7597385371425febdaa8c6a1da3625d4ffff16f5 < 43f8f7946814c8e5f464518246fdbc69b6e32326affected
LinuxLinux5.3affected
LinuxLinux0 < 5.3unaffected
LinuxLinux5.10.261 <= 5.10.*unaffected
LinuxLinux5.15.212 <= 5.15.*unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References