CVE-2026-90435 PUBLISHED

RDMA/mlx5: Fix integer overflow of user QP buffer size

Assigner: Linux
Reserved: 11.09.2026 Published: 17.09.2026 Updated: 17.09.2026

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

RDMA/mlx5: Fix integer overflow of user QP buffer size

set_user_buf_size() computes the QP buffer size by left-shifting the user-supplied rq.wqe_cnt and rq.wqe_shift values as signed integers. A sufficiently large rq.wqe_cnt causes signed integer overflow, which is undefined behavior, and yields a small or negative buf_size, causing ib_umem_get() to map a buffer smaller than the hardware will actually write into.

Replace the shifts and addition with check_shl_overflow() and check_add_overflow(), rejecting invalid user inputs.

Moreover, guard the identical shift computing qp->sq.offset in _create_user_qp() before set_user_buf_size() is reached.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to ccce6b7ef1d7efc59ccba3421e1339c6e63a3d20 (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to d99622e40aaa910ade681dfd4dc0fa240a011331 (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to c845e5e05140ea1bc64a5b1107942d93c876034d (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to 42fb8aefffff5b458aaa66803364a16e0ea44129 (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to d7fa2ff72ad1861eac194a4e0075d504ba8c246e (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to 5b6cfc6d7ff0959dd9766fdc24286a253b59ca77 (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to f917707f0de0832b8ab582391b1f64e549995c6c (excl.)
  • affected from e126ba97dba9edeb6fafa3665b5f8497fc9cdf8c to dec47e4b0fe34afdf38caa72b4408ba95502e5de (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 3.11 is affected
  • unaffected from 0 to 3.11 (excl.)
  • unaffected from 5.10.270 to 5.10.* (incl.)
  • unaffected from 5.15.221 to 5.15.* (incl.)
  • unaffected from 6.1.188 to 6.1.* (incl.)
  • unaffected from 6.6.157 to 6.6.* (incl.)
  • unaffected from 6.12.110 to 6.12.* (incl.)
  • unaffected from 6.18.52 to 6.18.* (incl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References