CVE-2026-90423

In the Linux kernel, the following vulnerability has been resolved:

RDMA/rxe: Fix UAF in ODP init error-handling path

rxe_odp_mr_init_user() stores &umem_odp->umem in mr->umem before

calling rxe_odp_init_pages(). If rxe_odp_init_pages() fails,

rxe_odp_mr_init_user() releases umem_odp and returns an error.

rxe_reg_user_mr() then unwinds the error through rxe_cleanup(),

rxe_mr_cleanup(), ib_umem_release(mr->umem). There is an

IS_ERR_OR_NULL(umem) check at the start of ib_umem_release().

But since mr->umem is NOT reset to NULL in the error handling

path of rxe_odp_mr_init_user(), the check passes and it reads

already-freed fields like umem->is_dmabuf, causing UAF.

Fix the UAF by clearing mr->umem after releasing the failed

ODP umem so the MR cleanup path does not release it again.