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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2026-90435
• https://git.kernel.org/stable/c/42fb8aefffff5b458aaa66803364a16e0ea44129
• https://git.kernel.org/stable/c/5b6cfc6d7ff0959dd9766fdc24286a253b59ca77
• https://git.kernel.org/stable/c/c845e5e05140ea1bc64a5b1107942d93c876034d
• https://git.kernel.org/stable/c/ccce6b7ef1d7efc59ccba3421e1339c6e63a3d20
• https://git.kernel.org/stable/c/d7fa2ff72ad1861eac194a4e0075d504ba8c246e
• https://git.kernel.org/stable/c/d99622e40aaa910ade681dfd4dc0fa240a011331
• https://git.kernel.org/stable/c/dec47e4b0fe34afdf38caa72b4408ba95502e5de
• https://git.kernel.org/stable/c/f917707f0de0832b8ab582391b1f64e549995c6c