High · published September 17, 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.