From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin King Subject: [PATCH][V2] cxgb4: fix signed wrap around when decrementing index idx Date: Thu, 22 Sep 2016 18:48:58 +0100 Message-ID: <20160922174858.31922-1-colin.king@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Cc: linux-kernel@vger.kernel.org To: Hariprasad S , netdev@vger.kernel.org Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:56425 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030559AbcIVRtB (ORCPT ); Thu, 22 Sep 2016 13:49:01 -0400 Sender: netdev-owner@vger.kernel.org List-ID: From: Colin Ian King Change predecrement compare to post decrement compare to avoid an unsigned integer wrap-around comparison when decrementing idx in the while loop. For example, when idx is zero, the current situation will predecrement idx in the while loop, wrapping idx to the maximum signed integer and cause out of bounds reads on rxq_info->msix_tbl[idx]. Signed-off-by: Colin Ian King --- drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c index d12a73e..42a9c8d 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c @@ -367,7 +367,7 @@ int request_msix_queue_irqs_uld(struct adapter *adap, unsigned int uld_type) } return 0; unwind: - while (--idx >= 0) { + while (idx-- > 0) { bmap_idx = rxq_info->msix_tbl[idx]; free_msix_idx_in_bmap(adap, bmap_idx); free_irq(adap->msix_info_ulds[bmap_idx].vec, -- 2.9.3