From 8eb6881c52cedf073295e3897d0d1b949802dac3 Mon Sep 17 00:00:00 2001 From: Timothy McDaniel Date: Wed, 2 Mar 2022 09:12:08 -0600 Subject: [PATCH] event/dlb2: add shift value check in sparse dequeue Add a check to ensure that all shift counts are valid. Shifting by more than 63 bits may result in undefined behavior, as noted during coverity scan. Coverity issue: 376527 Fixes: e697f35dbdd1 ("event/dlb2: update rolling mask used for dequeue") Cc: stable@dpdk.org Signed-off-by: Timothy McDaniel --- drivers/event/dlb2/dlb2.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/event/dlb2/dlb2.c b/drivers/event/dlb2/dlb2.c index 09abdd1660..7789dd74e0 100644 --- a/drivers/event/dlb2/dlb2.c +++ b/drivers/event/dlb2/dlb2.c @@ -3916,15 +3916,17 @@ dlb2_hw_dequeue_sparse(struct dlb2_eventdev *dlb2, &events[num], &qes[0], num_avail); - num += n_iter; - /* update rolling_mask for vector code support */ - m_rshift = qm_port->cq_rolling_mask >> n_iter; - m_lshift = qm_port->cq_rolling_mask << (64 - n_iter); - m2_rshift = qm_port->cq_rolling_mask_2 >> n_iter; - m2_lshift = qm_port->cq_rolling_mask_2 << + if (n_iter != 0) { + num += n_iter; + /* update rolling_mask for vector code support */ + m_rshift = qm_port->cq_rolling_mask >> n_iter; + m_lshift = qm_port->cq_rolling_mask << (64 - n_iter); + m2_rshift = qm_port->cq_rolling_mask_2 >> n_iter; + m2_lshift = qm_port->cq_rolling_mask_2 << (64 - n_iter); - qm_port->cq_rolling_mask = (m_rshift | m2_lshift); - qm_port->cq_rolling_mask_2 = (m2_rshift | m_lshift); + qm_port->cq_rolling_mask = (m_rshift | m2_lshift); + qm_port->cq_rolling_mask_2 = (m2_rshift | m_lshift); + } } else { /* !use_scalar */ num_avail = dlb2_recv_qe_sparse_vec(qm_port, &events[num], -- 2.39.5